Exposure apparatus, exposure method, method for producing device, and optical part

ABSTRACT

An exposure apparatus that exposes a substrate with light via liquid includes a stage which holds the substrate and is movable relative to a projection system; and a liquid supply system which supplies liquid onto the substrate held on the stage to form a liquid immersion area on part of the substrate The stage includes a substrate holder arranged in a recess of the stage to hold the substrate inside the recess so that an upper surface of the substrate is substantially flush with an upper surface of the stage around the recess; a flow passage connected to an internal space of the recess to remove liquid from the internal space; and a sensor which receives light from the projection optical system and is arranged so that an upper surface of the sensor is substantially flush with the upper surface of the stage around the recess.

This is a Division of U.S. patent application Ser. No. 14/697,374 filedApr. 27, 2015, which in turn is a Division of U.S. patent applicationSer. No. 11/639,245 filed Dec. 15, 2006 (now U.S. Pat. No. 9,019,469),which is a Division of U.S. patent application Ser. No. 10/581,307 filedSep. 29, 2006 (now U.S. Pat. No. 8,054,447), which is the U.S. NationalStage of PCT/JP2004/018435 filed Dec. 3, 2004. The disclosure of each ofthe prior applications is hereby incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present invention relates to an exposure apparatus, an exposuremethod, and a method for producing a device, in which an exposure lightbeam is radiated onto a substrate through a liquid to expose thesubstrate. The present invention also relates to an optical part whichis usable for a projection exposure apparatus using the liquid immersionmethod, and the projection exposure apparatus using the optical part.Further, the present invention relates to an optical part which ispreferably usable in such an environment that the optical part makescontact with a liquid or a vapor.

BACKGROUND ART

Semiconductor devices and liquid crystal display devices are produced bymeans of the so-called photolithography technique in which a patternformed on a mask is transferred onto a photosensitive substrate. Theexposure apparatus, which is used in the photolithography step, includesa mask stage for supporting the mask and a substrate stage forsupporting the substrate. The pattern on the mask is transferred ontothe substrate via a projection optical system while successively movingthe mask stage and the substrate stage. In recent years, it is demandedto realize the higher resolution of the projection optical system inorder to respond to the further advance of the higher integration of thedevice pattern. As the exposure wavelength to be used is shorter, theresolution of the projection optical system becomes higher. As thenumerical aperture of the projection optical system is larger, theresolution of the projection optical system becomes higher. Therefore,the exposure wavelength, which is used for the exposure apparatus, isshortened year by year, and the numerical aperture of the projectionoptical system is increased as well. The exposure wavelength, which isdominantly used at present, is 248 nm of the KrF excimer laser. However,the exposure wavelength of 193 nm of the ArF excimer laser, which isshorter than the above, is also practically used in some situations.When the exposure is performed, the depth of focus (DOF) is alsoimportant in the same manner as the resolution. The resolution R and thedepth of focus δ are represented by the following expressionsrespectively.

R=k ₁ ·λ/NA  (1)

δ=±k ₂ ·λ/NA ²  (2)

In the expressions, λ represents the exposure wavelength, NA representsthe numerical aperture of the projection optical system, and k₁ and k₂represent the process coefficients. According to the expressions (1) and(2), the following fact is appreciated. That is, when the exposurewavelength λ is shortened and the numerical aperture NA is increased inorder to enhance the resolution R, then the depth of focus δ isnarrowed.

If the depth of focus δ is too narrowed, it is difficult to match thesubstrate surface with respect to the image plane of the projectionoptical system. It is feared that the margin is insufficient during theexposure operation. Further, the optical part material, which is usablefor the exposure light beam that has the increasingly shortenedwavelength, is restricted. From the viewpoints as described above, theliquid immersion method has been suggested, which is disclosed, forexample, in International Publication No. 99/49504 and Japanese PatentApplication Laid-open No. 10-303114 as a method for substantiallyshortening the wavelength of the exposure light beam after passing viathe projection optical system and widening the depth of focus. In thisliquid immersion method, the space between the lower surface of theprojection optical system and the substrate surface is filled with aliquid such as water or any organic solvent to form a liquid immersionarea so that the resolution is improved and the depth of focus ismagnified about n times by utilizing the fact that the wavelength of theexposure light beam in the liquid is 1/n as compared with that in theair (n represents the refractive index of the liquid, which is about 1.2to 1.6 in ordinary cases).

As schematically shown in FIG. 18, an edge area E of a substrate P issometimes subjected to the exposure as well in the case of the exposureapparatus which adopts the liquid immersion method. In such a situation,a portion of the projection area 100 protrudes to the outside of thesubstrate P, and the exposure light beam is also radiated onto asubstrate table 120 for holding the substrate P. In the case of theliquid immersion exposure, the liquid immersion area of the liquid isformed so that the projection area 100 is covered therewith. However,when the edge area E is subjected to the exposure, then a part of theliquid immersion area of the liquid protrudes to the outside of thesubstrate P, and the liquid immersion area is also formed on thesubstrate table 120. When various measuring members and/or measuringsensors are arranged around the substrate P on the substrate table 120,the liquid immersion area is also formed on the substrate table 120 insome cases in order to use the measuring members and/or the measuringsensors. When a portion of the liquid immersion area is formed on thesubstrate table 120, then the liquid may remain on the substrate table120 highly possibly, and the following possibility arises.

That is, for example, the environment (temperature, humidity), in whichthe substrate P is placed, may be varied as a result of the vaporizationof the remained liquid, the substrate table 120 may be thermallydeformed, the environment of the optical paths for various measuringlight beams to measure, for example, the position information about thesubstrate P may be varied, and the exposure accuracy may be lowered.Further, the following possibility arises as well. That is, the watermark (trace of water) may remain after the vaporization of the remainedliquid, which may result in the factor of the pollution of, for example,the substrate P and the liquid, and which may result in the factor ofthe error concerning various types of measurements.

DISCLOSURE OF THE INVENTION

The present invention has been made taking the foregoing circumstancesinto consideration, a first object of which is to provide an exposureapparatus, an exposure method, and a method for producing a device, inwhich it is possible to prevent the liquid from remaining, and it ispossible to maintain a satisfactory exposure accuracy and a satisfactorymeasurement accuracy.

A second object of the present invention is to provide an optical partwhich has a water-repellent film provided with durability againstultraviolet laser irradiation, and a projection exposure apparatus whichis provided with the optical part.

In order to achieve the objects as described above, the presentinvention adopts the following constructions.

According to a first aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by radiating an exposurelight beam onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects an image of apattern onto the substrate; and a substrate table which holds thesubstrate; wherein a member, at least a part of a surface of which isliquid-repellent, is provided exchangeably on the substrate table.

According to the present invention, there is provided a method forproducing a device, comprising using the exposure apparatus according tothe aspect as described above.

According to the present invention, the liquid-repellent member, whichis provided on the substrate table, is provided exchangeably. Therefore,when the liquid repellence of the member is deteriorated, the member canbe exchanged with a new liquid-repellent member. Therefore, it ispossible to suppress the remaining of the liquid. Even when the liquidremains, the liquid can be recovered smoothly. Therefore, it is possibleto avoid the deterioration of the exposure accuracy and the measurementaccuracy which would be otherwise caused by the remaining liquid. It ispossible to produce the device which can exhibit desired performance.

According to a second aspect of the present invention, there is providedan exposure method for performing liquid immersion exposure for asubstrate by radiating an exposure light beam onto the substrate via aprojection optical system and a liquid; the exposure method comprisingholding the substrate with a substrate-holding member, thesubstrate-holding member having a flat portion which is disposed aroundthe substrate and which is substantially flush with a surface of thesubstrate; loading the substrate-holding member to a substrate stage,the substrate-holding member holding the substrate; performing theliquid immersion exposure for the substrate loaded onto the substratestage; and unloading the substrate-holding member with which thesubstrate is held from the substrate stage after completion of theliquid immersion exposure.

According to the present invention, there is provided a method forproducing a device, comprising using the exposure method as describedabove.

According to the present invention, the substrate-holding member, whichhas the flat portion around the substrate, is loaded and unloaded withrespect to the substrate stage together with the substrate. Accordingly,the substrate-holding member can be easily exchanged with respect to thesubstrate stage together with the substrate. For example, even when theliquid repellence of the substrate-holding member is deteriorated, it iseasy to perform the exchange. The substrate-holding member has the flatportion around the substrate. Therefore, when the substrate-holdingmember is loaded to the substrate stage together with the substrate, andthe liquid immersion exposure for the edge area of the substrate isperformed, the shape of the liquid immersion area is maintained by theflat portion, even when a part of the liquid immersion area of theliquid protrudes to the outside of the substrate. It is possible toperform the liquid immersion exposure in a state in which the liquid issatisfactorily retained below the projection optical system, withoutcausing, for example, the outflow of the liquid. Therefore, thedeterioration of the exposure accuracy is avoided, and it is possible toproduce the device which exhibits desired performance.

According to a third aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by radiating an exposurelight beam onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects an image of apattern onto the substrate; and a movable stage which is movablerelative to the projection optical system; wherein a liquid-repellentmember, at least a part of which is liquid-repellent, is provided on themovable stage, and the liquid-repellent member is exchangeable.

In the exposure apparatus according to the third aspect of the presentinvention, the liquid-repellent member, which is provided on the movablestage, is provided exchangeably. Therefore, when the liquid repellenceof the member is deteriorated, the member can be exchanged with a newmember. The movable stage may be a substrate stage which is movablewhile holding the substrate, or a measuring stage which is provided withvarious reference members and/or measuring members such as measuringsensors. Alternatively, the exposure apparatus may include, as themovable stage, both of a substrate stage and a measuring stage. Further,the exposure apparatus may include, as the movable stage, a plurality ofsubstrate stages or a plurality of measuring stages.

According to a fourth aspect of the present invention, there is providedan exposure method for performing liquid immersion exposure for asubstrate by radiating an exposure light beam onto the substrate througha liquid; the exposure method comprising supplying the liquid to atleast a part of a surface of the substrate; and performing the liquidimmersion exposure for the substrate by radiating the exposure lightbeam onto the substrate through the liquid; wherein a part of theexposure apparatus, which is different from the substrate for which theliquid is supplied, is liquid-repellent, and the liquid-repellent partof the exposure apparatus is exchanged depending on deterioration ofliquid repellence thereof.

In the exposure method according to the fourth aspect of the presentinvention, even when the liquid-repellent part of the exposure apparatusis deteriorated by being irradiated with the ultraviolet light, it ispossible to avoid, for example, the remaining and the leakage of theliquid which would be caused by the deterioration, because theconcerning part is exchanged depending on the deterioration. The partmay be exchanged periodically. Alternatively, the part may be exchangedon the basis of the result of the observation or the estimation of thesituation of deterioration for every part.

rewritten paragraph:

According to a fifth aspect of the present invention, there is providedan optical part to be provided on a substrate stage of a projectionexposure apparatus which illuminates a mask with an exposure light beamand transfers a pattern of the mask through a liquid onto a substrateheld by the substrate stage by using a projection optical system; theoptical part comprising a light irradiated surface which is irradiatedwith the exposure light beam; an adhesive particulate layer whichcomprises a particulate layer composed of at least one of silicondioxide, magnesium fluoride, and calcium fluoride, and formed on thelight irradiated surface; and a water-repellent film which is composedof an amorphous fluororesin and formed on a surface of the adhesiveparticulate layer.

The inventors performed analysis about the adhesiveness between the basematerial glass and fluoroalkylsilane, and found that any chemical bond,which is based on, for example, the hydrogen bond and/or thecondensation reaction, cannot be expected between fluoroalkylsilane andthe base material glass, because the terminal group —CF₃ offluoroalkylsilane is chemically stable. Accordingly, the inventors havemade the investigation about the method for increasing theintermolecular attractive force without depending on the chemical bond.As a result, the inventors have succeeded in the increase in theadhesion energy in a skillful manner by increasing the surface area ofthe adhesive layer which is to be adhered to the base material glass.According to the optical part of the present invention, the particulateor fine particle layer, which is composed of at least one of silicondioxide (SiO₂), magnesium fluoride (MgF₂), and calcium fluoride (CaF₂)for forming the adhesive particulate layer, has the good affinity forthe glass (main component: SiO₂) of the base material, wherein a properor appropriate degree of adhesiveness is obtained. Further,irregularities, which result from diameters of the particles orparticulates, are generated on the surface. Further, silicon dioxide orthe like is such a material that the ultraviolet transmittance isextremely high. Therefore, such a material itself has the highdurability against the laser irradiation as well. Therefore, when theparticulate layer, which is composed of at least one of silicon dioxide(SiO₂), magnesium fluoride (MgF₂), and calcium fluoride (CaF₂), isformed as a film, and the water-repellent film, which is composed of theamorphous fluororesin, is formed thereafter, then the amorphousfluororesin enters voids or interstices of particulates of silicondioxide or the like, and the amorphous fluororesin is subjected todrying and solidification while effecting embrace and inclusion of theparticles. The mechanical strength of the amorphous fluororesin itselfis high. Therefore, the water-repellent film, which is allowed to maketight contact with the base material, has the high strength.

According to a sixth aspect of the present invention, there is providedan optical part to be provided on a substrate stage of a projectionexposure apparatus for illuminating a mask with an exposure light beamand transferring a pattern of the mask through a liquid onto a substrateheld by the substrate stage by using a projection optical system; theoptical part comprising a light irradiated surface which is irradiatedwith the exposure light beam; an adhesive surface which is formed on thelight irradiated surface; and a water-repellent film which is composedof an amorphous fluororesin and formed on the adhesive surface. In theoptical part of this aspect, it is preferable that the adhesive surfaceis a surface subjected to etching with hydrogen fluoride.

According to the optical part of the sixth aspect, the adhesive surface,which is constructed of the etching surface subjected to the etchingwith hydrogen fluoride, for example, is provided for the lightirradiated surface. Therefore, when the water-repellent film, which iscomposed of the amorphous fluororesin, is formed on the adhesivesurface, the amorphous fluororesin is subjected to drying andsolidification while effecting embrace and inclusion. The mechanicalstrength of the amorphous fluororesin itself is high. Therefore, thewater-repellent film, which is allowed to make tight contact with thebase material, has the high strength.

In the optical part according to the aspect described above, the lightirradiated surface may have a base material glass. In the optical partaccording to the aspect described above, the irradiated surface may havea metal film which is formed on at least a part or portion of the basematerial glass. According to the optical part as described above, thewater-repellent film, which is formed on the light irradiated surface,has the durability against the laser irradiation. Therefore, it ispossible to maintain the water repellence of the light irradiatedsurface of the optical part provided on the substrate stage of theprojection exposure apparatus for a long period of time.

According to the present invention, there is also provided a projectionexposure apparatus comprising the optical part according to any one ofthe aspects described above. According to this projection exposureapparatus, the optical part, which makes it possible to maintain thewater repellence of the light irradiated surface for a long period oftime, is provided on the substrate stage. Therefore, even when theliquid immersion exposure is repeatedly performed, it is possible toreliably discharge water from the light irradiated surface of theoptical part.

According to a seventh aspect of the present invention, there isprovided a projection exposure apparatus which illuminates a mask withan exposure light beam and transfers a pattern of the mask through aliquid onto a substrate held by a substrate stage by using a projectionoptical system; the projection exposure apparatus comprising, on thesubstrate stage, an optical part including a light irradiated surfacewhich is irradiated with the exposure light beam; an adhesiveparticulate layer which is formed on the light irradiated surface; and awater-repellent film which is composed of an amorphous fluororesin andformed on a surface of the adhesive particulate layer.

According to the projection exposure apparatus of the seventh aspect,the optical part, which is provided on the substrate stage, has theadhesive particulate layer on the light irradiated surface. Therefore,the water-repellent film, which is composed of the amorphousfluororesin, makes tight contact with the adhesive particulate layer.The mechanical strength of the amorphous fluororesin itself is high.Therefore, the water-repellent film, which is allowed to make tightcontact with the base material, has the high strength.

In the projection exposure apparatus of the seventh aspect, the lightirradiated surface may have a base material glass. In the projectionexposure apparatus of the seventh aspect, the light irradiated surfacemay have a metal film which is formed on at least a part or portion ofthe base material glass. According to the projection exposure apparatusas described above, the water-repellent film, which is formed on thelight irradiated surface of the optical part mounted on the substratestage, has the durability against the laser irradiation. Therefore, itis possible to maintain the water repellence of the light irradiatedsurface of the optical part mounted on the substrate stage of theprojection exposure apparatus for a long period of time.

According to an eighth aspect of the present invention, there isprovided an optical part comprising a part body which has a lightirradiated surface; a particulate layer which is formed of at least oneparticulate selected from the group consisting of silicon dioxide,magnesium fluoride, and calcium fluoride, and formed on the lightirradiated surface; and a water-repellent film which is formed of anamorphous fluororesin, on a surface of the particulate layer. Thewater-repellent film is strongly connected to the light irradiatedsurface by the aid of the particulate layer. Therefore, the presentinvention is extremely useful for the way of use including, for example,optical sensors and lenses to be used in the liquid or vapor atmosphere.

According to a ninth aspect of the present invention, there is providedan optical part comprising a part body which has a light irradiatedsurface; an adhesive surface which is formed by etching on the lightirradiated surface; and a water-repellent film which is formed of anamorphous fluororesin, on the adhesive surface. The water-repellent filmis strongly connected to the light irradiated surface by the aid of theparticulate layer. Therefore, the present invention is extremely usefulfor the way of use including, for example, optical sensors and lenses tobe used in the liquid or vapor atmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic arrangement illustrating an embodiment of anexposure apparatus of the present invention.

FIG. 2 shows a schematic plan view illustrating a liquid supplymechanism and a liquid recovery mechanism.

FIG. 3 shows a plan view illustrating a substrate table.

FIG. 4 shows a plan view illustrating the substrate table in a state inwhich a substrate is held.

FIG. 5 shows a sectional view illustrating the substrate table.

FIG. 6 schematically shows that respective members are detachable withrespect to the substrate table.

FIGS. 7(a) to 7(d) schematically show an example of the operation of theexposure apparatus of the present invention.

FIGS. 8(a) to 8(d) schematically show an example of the operation of theexposure apparatus of the present invention.

FIG. 9 shows a plan view illustrating a substrate-holding membertransported by a transport unit.

FIG. 10 shows a sectional view illustrating another embodiment of asubstrate table.

FIGS. 11(a) and 11(b) show a schematic arrangement illustrating anotherembodiment of an exposure apparatus of the present invention.

FIGS. 12(a) and 12(b) show another embodiment of a substrate-holdingmember.

FIGS. 13(a) to 13(d) schematically show another example of the operationof the exposure apparatus of the present invention.

FIG. 14 shows a schematic arrangement illustrating another embodiment ofan exposure apparatus of the present invention.

FIG. 15 shows a schematic arrangement illustrating another embodiment ofan exposure apparatus of the present invention.

FIG. 16 shows a schematic arrangement illustrating another embodiment ofan exposure apparatus of the present invention.

FIG. 17 shows a flow chart illustrating exemplary steps of producing asemiconductor device.

FIG. 18 schematically explains a problem involved in the conventionaltechnique.

FIG. 19 shows optical parts provided on a wafer stage according to anembodiment.

FIG. 20 shows a construction of the optical part provided on the waferstage according to the embodiment.

FIG. 21 shows a construction of the optical part provided on the waferstage according to the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

An explanation will be made below about the exposure apparatus accordingto the present invention with reference to the drawings. However, thepresent invention is not limited thereto.

First Embodiment

FIG. 1 shows a schematic arrangement illustrating an embodiment of theexposure apparatus of the present invention. With reference to FIG. 1,an exposure apparatus EX includes a mask stage MST which supports a maskM, a substrate stage PST which supports a substrate P by the aid of asubstrate table PT, an illumination optical system IL which illuminates,with an exposure light beam EL, the mask M supported by the mask stageMST, a projection optical system PL which performs projection exposurefor the substrate P supported by the substrate stage PST with an imageof a pattern of the mask M illuminated with the exposure light beam EL,and a control unit CONT which integrally controls the overall operationof the exposure apparatus EX.

The liquid immersion method is applied to the exposure apparatus EX ofthe embodiment of the present invention in order that the exposurewavelength is substantially shortened to improve the resolution and thedepth of focus is substantially widened. The liquid immersion exposureapparatus includes a liquid supply mechanism 10 which supplies theliquid 1 onto the substrate P, and a liquid recovery mechanism 20 whichrecovers the liquid 1 from the surface of the substrate P. In embodimentof the present invention, pure water is used as the liquid 1. Theexposure apparatus EX forms a liquid immersion area AR2 (locally) on atleast a part of the substrate P including a projection area AR1 of theprojection optical system PL by the liquid 1 supplied from the liquidsupply mechanism 10 at least during the period in which the image of thepattern of the mask M is transferred onto the substrate P. Specifically,the exposure apparatus EX is operated as follows. That is, the spacebetween the surface (exposure surface) of the substrate P and theoptical element 2 disposed at the end portion of the projection opticalsystem PL is filled with the liquid 1. The image of the pattern of themask M is projected onto the substrate P to expose the substrate Ptherewith via the projection optical system PL and the liquid 1 disposedbetween the projection optical system PL and the substrate P.

The embodiment of the present invention will now be explained asexemplified by a case of the use of the scanning type exposure apparatus(so-called scanning stepper) as the exposure apparatus EX in which thesubstrate P is exposed with the pattern formed on the mask M whilesynchronously moving the mask M and the substrate P in mutuallydifferent directions (opposite directions) in the scanning directions.In the following explanation, the Z axis direction is the directionwhich is coincident with the optical axis AX of the projection opticalsystem PL, the X axis direction is the synchronous movement direction(scanning direction) for the mask M and the substrate P in the planeperpendicular to the Z axis direction, and the Y axis direction(non-scanning direction) is the direction which is perpendicular to theZ axis direction and the X axis direction. The directions of rotation(inclination) about the X axis, the Y axis, and the Z axis aredesignated as θX, θY, and θZ directions respectively. The term“substrate” referred to herein includes those obtained by coating asemiconductor wafer surface with a photoresist as a photosensitivematerial, and the term “mask” includes a reticle formed with a devicepattern to be subjected to the reduction projection onto the substrate.

The illumination optical system IL is used so that the mask M, which issupported on the mask stage MST, is illuminated with the exposure lightbeam EL. The illumination optical system IL includes, for example, anexposure light source, an optical integrator (homogenizer) whichuniformizes the illuminance of the light flux radiated from the exposurelight source, a condenser lens which collects the exposure light beam ELemitted from the optical integrator, a relay lens system, and a variablefield diaphragm which sets the illumination area on the mask Milluminated with the exposure light beam EL to be slit-shaped. Thepredetermined illumination area on the mask M is illuminated with theexposure light beam EL having a uniform illuminance distribution by theillumination optical system IL. Those usable as the exposure light beamEL radiated from the illumination optical system IL include, forexample, emission lines (g-ray, h-ray, i-ray) radiated, for example,from a mercury lamp, far ultraviolet light beams (DUV light beams) suchas the KrF excimer laser beam (wavelength: 248 nm), and vacuumultraviolet light beams (VUV light beams) such as the ArF excimer laserbeam (wavelength: 193 nm) and the F₂ laser beam (wavelength: 157 nm). Inthis embodiment, the ArF excimer laser beam is used. As described above,the liquid 1 is pure water in this embodiment, through which theexposure light beam EL is transmissive even when the exposure light beamEL is the ArF excimer laser beam. The emission line (g-ray, h-ray,i-ray) and the far ultraviolet light beam (DUV light beam) such as theKrF excimer laser beam (wavelength: 248 nm) are also transmissivethrough pure water.

The mask stage MST supports the mask M, while the mask stage MST istwo-dimensionally movable in the plane perpendicular to the optical axisAX of the projection optical system PL, i.e., in the XY plane, and it isfinely rotatable in the OZ direction. The mask stage MST is driven by amask stage-driving unit MSTD such as a linear motor. The maskstage-driving unit MSTD is controlled by the control unit CONT. Amovement mirror 50 is provided on the mask stage MST. A laserinterferometer 51 is provided at a position opposed to the movementmirror 50. The position in the two-dimensional direction and the angleof rotation of the mask M on the mask stage MST are measured inreal-time by the laser interferometer 51. The result of the measurementis outputted to the control unit CONT. The control unit CONT drives themask stage-driving unit MSTD on the basis of the result of themeasurement obtained by the laser interferometer 51 to thereby positionthe mask M supported on the mask stage MST.

The projection optical system PL projects the pattern on the mask M ontothe substrate P at a predetermined projection magnification a to performthe exposure. The projection optical system PL includes a plurality ofoptical elements including the optical element (lens) 2 provided at theend portion on the side of the substrate P. The optical elements aresupported by a barrel PK. In this embodiment, the projection opticalsystem PL is based on the reduction system having the projectionmagnification β which is, for example, ¼ or ⅕. The projection opticalsystem PL may be any one of the 1× magnification system and themagnifying system. The projection optical system PL may be any one ofthe catoptric system including no dioptric element, the dioptric systemincluding no catoptric element, and the catadioptric system includingdioptric and catoptric elements. The optical element 2, which isdisposed at the end portion of the projection optical system PL of thisembodiment, is provided detachably (exchangeably) with respect to thebarrel PK. The liquid 1 in the liquid immersion area AR2 makes contactwith the optical element 2.

The optical element 2 is formed of fluorite. Water has a high affinityfor fluorite. Therefore, the liquid 1 is successfully allowed to maketight contact with the substantially entire surface of the liquidcontact surface 2 a of the optical element 2. That is, in thisembodiment, the water, which has the high affinity for the liquidcontact surface 2 a of the optical element 2, is supplied as the liquid1. Therefore, the highly tight contact is effected between the liquid 1and the liquid contact surface 2 a of the optical element 2. The opticalpath, which is disposed between the optical element 2 and the substrateP, can be reliably filled with the liquid 1. The optical element 2 maybe quartz having a high affinity for water as well. A water-attracting(lyophilic or liquid-attracting) treatment may be performed to theliquid contact surface 2 a of the optical element 2 to further enhancethe affinity for the liquid 1. The barrel PK makes contact with theliquid (water) 1 at portions disposed in the vicinity of the endportion. Therefore, at least the portions disposed in the vicinity ofthe end portion are formed of a metal such as Ti (titanium) which hasthe resistance against rust.

The substrate stage PST supports the substrate P. The substrate stagePST includes a Z stage 52 which holds the substrate P by the aid of thesubstrate table PT, an XY stage 53 which supports the Z stage 52, and abase 54 which supports the XY stage 53. The substrate table PT holds thesubstrate P. The substrate table PT is provided on the substrate stagePST (Z stage 52). The substrate stage PST is driven by a substratestage-driving unit PSTD such as a linear motor. The substratestage-driving unit PSTD is controlled by the control unit CONT. Bydriving the Z stage 52, the substrate P held by the substrate table PTis subjected to the control of the position in the Z axis direction(focus position) and the positions in the θX and θY directions. Bydriving the XY stage 53, the substrate P is subjected to the control ofthe position in the XY directions (position in the directionsubstantially parallel to the image plane of the projection opticalsystem PL). That is, the Z stage 52 controls the focus position and theangle of inclination of the substrate P so that the surface of thesubstrate P is adjusted to match the image plane of the projectionoptical system PL in the auto-focus manner and the auto-leveling manner,and the XY stage 53 positions the substrate P in the X axis directionand the Y axis direction. It goes without saying that the Z stage andthe XY stage may be provided as an integrated body. Those usable for theauto-focus/auto-leveling detecting system include, for example, anarrangement disclosed in Japanese Patent Application Laid-open No.8-37149.

A movement mirror 55, which is movable together with the substrate stagePST with respect to the projection optical system PL, is provided on thesubstrate stage PST (substrate table PT). A laser interferometer 56 isprovided at a position opposed to the movement mirror 55. The angle ofrotation and the position in the two-dimensional direction of thesubstrate P on the substrate stage PST (substrate table PT) are measuredin real-time by the laser interferometer 56. The result of themeasurement is outputted to the control unit CONT. The control unit CONTdrives the substrate stage-driving unit PSTD on the basis of the resultof the measurement of the laser interferometer 56 to thereby positionthe substrate P supported on the substrate stage PST.

A substrate alignment system 350, which detects the alignment mark onthe substrate P or the reference mark (described later on) provided onthe substrate stage PST (substrate table PT), is arranged over thosedisposed in the vicinity of the substrate stage PST (substrate tablePT). A mask alignment system 360, which detects the reference markprovided on the substrate stage PST (substrate table PT) via the mask Mand the projection optical system PL by using a light beam having thesame wavelength as that of the exposure light beam EL, is provided inthe vicinity of the mask stage MST. Those usable for the arrangement ofthe substrate alignment system 350 include, for example, one disclosedin Japanese Patent Application Laid-open No. 4-65603 (corresponding toU.S. Pat. No. 5,493,403). Those usable for the arrangement of the maskalignment system 360 include, for example, one disclosed in JapanesePatent Application Laid-open No. 7-176468 (corresponding to U.S. Pat.No. 5,646,413).

A plate member 30, which surrounds the substrate P held by the substratetable PT, is provided on the substrate table PT. The plate member 30 isa member distinct from the substrate table PT. The plate member 30 isprovided detachably with respect to the substrate table PT, and theplate member 30 is exchangeable. The plate member 30 has a flat surface(flat portion) 30A which is substantially flush with the surface of thesubstrate P held by the substrate table PT. The flat surface 30A isarranged around the substrate P held by the substrate table PT. Further,a second plate member 32, which has a flat surface 32A substantiallyflush with the flat surface 30A of the plate member 30, is providedoutside the plate member 30 on the substrate table PT. The second platemember 32 is provided detachably with respect to the substrate table PTas well, and the second plate member 32 is exchangeable.

The liquid supply mechanism 10, which supplies the predetermined liquid1 onto the substrate P, includes a first liquid supply section 11 and asecond liquid supply section 12 which are capable of supplying theliquid 1, a first supply member 13 which is connected to the firstliquid supply section 11 via a supply tube 11A having a flow passage andwhich has a supply port 13A for supplying the liquid 1 fed from thefirst liquid supply section 11 onto the substrate P, and a second supplymember 14 which is connected to the second liquid supply section 12 viaa supply tube 12A having a flow passage and which has a supply port 14Afor supplying the liquid 1 fed from the second liquid supply section 12onto the substrate P. The first and second supply members 13, 14 arearranged closely to the surface of the substrate P, and they areprovided at mutually different positions in the surface direction of thesubstrate P. Specifically, the first supply member 13 of the liquidsupply mechanism 10 is provided on one side (−X side) in the scanningdirection with respect to the projection area AR1. The second supplymember 14 is provided on the other side (+X side) in the scanningdirection with respect to the projection area AR1.

Each of the first and second liquid supply sections 11, 12 includes, forexample, a tank for accommodating the liquid 1, and a pressurizing pump(these components are not shown). The first and second liquid supplysections 11, 12 supply the liquid 1 onto the substrate P via the supplytubes 11A, 12A and the supply members 13, 14 respectively. The operationof each of the first and second liquid supply sections 11, 12 forsupplying the liquid is controlled by the control unit CONT. The controlunit CONT is capable of controlling the liquid supply amounts per unittime onto the substrate P by the first and second liquid supply sections11, 12 independently respectively. Each of the first and second liquidsupply sections 11, 12 includes a temperature-adjusting mechanism forthe liquid. The liquid 1, which has approximately the same temperature(for example, 23° C.) as the temperature in the chamber foraccommodating the apparatus therein, can be supplied onto the substrateP by the temperature-adjusting mechanism. It is not necessarilyindispensable that the exposure apparatus EX is provided with the tank,the pressurizing pump, and the temperature-adjusting mechanism of eachof the liquid supply sections 11, 12 which may be replaced with theequipment of the factory or the like in which the exposure apparatus EXis installed.

The liquid recovery mechanism 20 recovers the liquid 1 from the surfaceof the substrate P. The liquid recovery mechanism 20 includes first andsecond recovery members 23, 24 each of which has a recovery port 23A,24A arranged closely to the surface of the substrate P, and first andsecond liquid recovery sections 21, 22 which are connected to the firstand second recovery members 23, 24 via recovery tubes 21A, 22A havingflow passages respectively. Each of the first and second liquid recoverysections 21, 22 includes, for example, a vacuum system (sucking unit)such as a vacuum pump, a gas/liquid separator, and a tank foraccommodating the recovered liquid 1 (these components are not shown).The first and second liquid recovery sections 21, 22 recover the liquid1 from the surface of the substrate P via the first and second recoverymembers 23, 24 and the recovery tubes 21A, 22A, respectively. Theoperation of each of the first and second liquid recovery sections 21,22 for recovering the liquid is controlled by the control unit CONT. Thecontrol unit CONT is capable of controlling the liquid recovery amountsper unit time by the first and second liquid recovery sections 21, 22independently respectively. It is not necessarily indispensable that theexposure apparatus EX is provided with the vacuum system, the gas/liquidseparator, and the tank of each of the liquid recovery sections 21, 22which may be replaced with the equipment of the factory or the like inwhich the exposure apparatus EX is installed.

FIG. 2 shows a plan view illustrating a schematic arrangement of theliquid supply mechanism 10 and the liquid recovery mechanism 20. Asshown in FIG. 2, the projection area AR1 of the projection opticalsystem PL is designed to have a slit shape (rectangular shape) in whichthe Y axis direction (non-scanning direction) is the longitudinaldirection. The liquid immersion area AR2, which is filled with theliquid 1, is formed on a part of the substrate P so that the projectionarea AR1 is included therein. The first supply member 13 of the liquidsupply mechanism 10, which is used to form the liquid immersion area AR2of the projection area AR1, is provided on one side (−X side) in thescanning direction with respect to the projection area AR1, and thesecond supply member 14 is provided on the other side (+x side).

The first and second supply members 13, 14 are formed to besubstantially circular arc-shaped respectively as viewed in a plan view.The size in the Y axis direction of the supply port 13A, 14A is designedto be larger than at least the size in the Y axis direction of theprojection area AR1. The supply ports 13A, 14A, which are formed to besubstantially circular arc-shaped as viewed in a plan view, are arrangedto interpose the projection area AR1 in relation to the scanningdirection (X axis direction). The liquid supply mechanism 10simultaneously supplies the liquid 1 on the both sides of the projectionarea AR1 by the aid of the supply ports 13A, 14A of the first and secondsupply members 13, 14.

Each of the first and second recovery members 23, 24 of the liquidrecovery mechanism 20 has a recovery port 23A, 24A which is formedcontinuously to be circular arc-shaped so that the recovery port 23A,24A is directed to the surface of the substrate P. A substantiallyannular recovery port is formed by the first and second recovery members23, 24 which are arranged so that they are opposed to one another. Therecovery ports 23A, 24A of the first and second recovery members 23, 24respectively are arranged to surround the projection area AR1 and thefirst and second supply members 13, 14 of the liquid supply mechanism10.

The liquid 1, which is supplied onto the substrate P from the supplyports 13A, 14A of the first and second supply members 13, 14, issupplied so that the liquid 1 is spread while causing the wettingbetween the substrate P and the lower end surface of the end portion(optical element 2) of the projection optical system PL. The liquid 1,which outflows to the outside of the first and second supply members 13,14 with respect to the projection area AR1, is recovered from therecovery ports 23A, 24A of the first and second recovery members 23, 24which are arranged outside with respect to the projection area AR1 ascompared with the first and second supply members 13, 14.

In this embodiment, when the substrate P is subjected to the scanningexposure, the liquid supply amount per unit time, which is supplied infront of the projection area AR1 in relation to the scanning direction,is set to be larger than the liquid supply amount supplied from the sideopposite thereto. For example, when the exposure process is performedwhile moving the substrate P in the +X direction, the control unit CONTis operated so that the liquid amount, which is supplied from the −xside (i.e., from the supply port 13A) with respect to the projectionarea AR1, is larger than the liquid amount which is supplied from the +Xside (i.e., from the supply port 14A). On the other hand, when theexposure process is performed while moving the substrate P in the −Xdirection, the control unit CONT is operated so that the liquid amount,which is supplied from the +X side with respect to the projection areaAR1, is larger than the liquid amount which is supplied from the −Xside. The liquid recovery amount per unit time, which is recovered infront of the projection area AR1 in relation to the scanning direction,is set to be smaller than the liquid recovery amount on the sideopposite thereto. For example, when the substrate P is moved in the +Xdirection, the recovery amount, which is recovered from the +X side(i.e., from the recovery port 24A) with respect to the projection areaAR1, is larger than the recovery amount which is recovered from the −Xside (i.e., from the recovery port 23A).

The mechanism, with which the liquid immersion area AR2 is locallyformed on the substrate P (substrate stage PST), is not limited to themechanism as described above. It is also possible to adopt, for example,mechanisms disclosed in United States Patent Application Publication No.2004/020782 and International Publication No. 2004/055803, the contentof which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

FIG. 3 shows a plan view illustrating the substrate table PT as viewedfrom an upper position. FIG. 4 shows a plan view illustrating thesubstrate table PT which holds the substrate P as viewed from an upperposition. With reference to FIGS. 3 and 4, movement mirrors 55 arearranged at two edge portions of the substrate table PT which isrectangular as viewed in a plan view, the two edge portions beingperpendicular to one another. A recess 31 is formed at a substantiallycentral portion of the substrate table PT. The substrate holder PH,which constructs a part of the substrate table PT, is arranged in therecess 31. The substrate P is held by the substrate holder PH. The platemember 30, which has the flat surface 30A having approximately the sameheight as that of (being flush with) the surface of the substrate P, isprovided around the substrate P (substrate holder PH). The plate member30 is an annular member, which is arranged to surround the substrateholder PH (substrate P). The plate member 30 is formed of a materialhaving the liquid repellence such as fluoride including, for example,polytetrafluoroethylene (Teflon (trade name)). The liquid immersion areaAR2 can be satisfactorily formed on the image plane side of theprojection optical system PL even when the edge area E of the substrateP is subjected to the liquid immersion exposure, because the platemember 30, which has the flat surface 30A substantially flush with thesurface of the substrate P, is provided around the substrate P.

It is also allowable that any difference in height is present betweenthe surface of the substrate P and the flat surface 30A of the platemember 30, on condition that the liquid immersion area AR2 can be formedto fill the optical path space on the image plane side of the projectionoptical system PL with the liquid 1. For example, the flat surface 30Amay be lower than the surface of the substrate P in relation to the Zdirection.

As shown in FIGS. 1, 3, and 4, the second plate member 32 is providedoutside the plate member 30 (substrate holder PH) on the substrate tablePT. The second plate member 32 has the flat surface 32A which hassubstantially the same height as that of (is flush with) the surface ofthe substrate P and the flat surface 30A of the plate member 30. Thesecond plate member 32 is provided to cover the substantially entireregion of the upper surface of the substrate table PT except for thesubstrate holder PH (substrate P) and the plate member 30. The secondplate member 32 is also formed of a material having the liquidrepellence including, for example, polytetrafluoroethylene.

The contact angle of the liquid 1 on the surface of the flat surface 30Aof the plate member 30 and the contact angle of the liquid 1 on thesurface of the flat surface 32A of the second plate member 32 are notless than 110° respectively in the initial state before the exposurelight beam EL is radiated.

A plurality of openings 32K, 32L, 32N are formed at predeterminedpositions of the second plate member 32. A reference member 300 isarranged in the opening 32K. A reference mark PFM to be detected by asubstrate alignment system 350 and a reference mark MFM to be detectedby a mask alignment system 360 are provided in a predeterminedpositional relationship on the reference member 300. The referencemember 300 has an upper surface 301A which is a substantially flatsurface. The upper surface 301A may be used as a reference plane for thefocus/leveling-detecting system as well. Further, the upper surface 301Aof the reference member 300 is provided to have approximately the sameheight as those of (be flush with) the surface of the substrate P, thesurface (flat surface) 30A of the plate member 30, and the surface (flatsurface) 32A of the second plate member 32. The reference member 300 isformed to be rectangular as viewed in a plan view. A gap K is formedbetween the second plate member 32 and the reference member 300 arrangedin the opening 32K. In this embodiment, the gap K is, for example, about0.3 mm.

An uneven illuminance sensor 400 as an optical sensor is arranged in theopening 32L. The uneven illuminance sensor is disclosed, for example, inJapanese Patent Application Laid-open No. 57-117238 (corresponding toU.S. Pat. No. 4,465,368), the content of which are incorporated hereinby reference within a range of permission of the domestic laws andordinances of the state designated or selected in this internationalapplication. An upper surface 401A of an upper plate 401 of the unevenilluminance sensor 400 is a substantially flat surface, which isprovided to have approximately the same height as those of (be flushwith) the surface of the substrate P, the surface 30A of the platemember 30, and the surface 32A of the second plate member 32. A pinhole470, through which the light can pass, is provided for the upper surface401A of the uneven illuminance sensor 400. Portions of the upper surface401A of the light-transmissive upper plate 401 except for the pinhole470 are covered with a light-shielding material such as chromium. Theuneven illuminance sensor 400 (upper plate 401) is formed to berectangular as viewed in a plan view. A gap L is formed between thesecond plate member 32 and the uneven illuminance sensor 400 (upperplate 401) arranged in the opening 32L. In this embodiment, the gap Lis, for example, about 0.3 mm.

A spatial image-measuring sensor 500 as an optical sensor is arranged inthe opening 32N. The spatial image-measuring sensor 500 is disclosed,for example, in Japanese Patent Application Laid-open No. 2002-14005(corresponding to United States Patent Application Publication No.2002/0041377), the content of which are incorporated herein by referencewithin a range of permission of the domestic laws and ordinances of thestate designated or selected in this international application. An uppersurface 501A of an upper plate 501 of the spatial image-measuring sensor500 is a substantially flat surface, which may be used as a referenceplane for the focus/leveling-detecting system as well. The upper surface501A is provided to have approximately the same height as those of (beflush with) the surface of the substrate P, the surface 30A of the platemember 30, and the surface 32A of the second plate member 32. A slit570, through which the light can pass, is provided for the upper surface501A of the spatial image-measuring sensor 500. Portions of the uppersurface 501A of the light-transmissive upper plate 501 except for theslit 570 are covered with a light-shielding material such as chromium.The spatial image-measuring sensor 500 (upper plate 501) is formed to berectangular as viewed in a plan view. A gap N is formed between thespatial image-measuring sensor 500 (upper plate 501) and the opening32N. In this embodiment, the gap N is in approximately the same degreeas the production tolerance or margin for the outer shape of thesubstrate P, for example, about 0.3 mm. As described above, thesubstrate table PT, which holds the substrate P, has the upper surfacewhich is substantially flush over the entire surface.

It is also allowable that any mutual difference in height is present inrelation to the flat surface 30A of the plate member 30, the surface 32Aof the second plate member 32, the upper surface 301A of the referencemember 300, the upper surface 401A of the uneven illuminance sensor 400,and the upper surface 501A of the spatial image-measuring sensor 500, oncondition that the liquid immersion area AR2 can be formed to fill theoptical path space on the image plane side of the projection opticalsystem PL with the liquid 1.

Although not shown, the substrate table PT is also provided with aradiation amount sensor (illuminance sensor) which is arranged in anopening formed for the second plate member 32. The radiation amountsensor is disclosed, for example, in Japanese Patent ApplicationLaid-open No. 11-16816 (corresponding to United States PatentApplication Publication No. 2002/0061469), the content of which areincorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application.

The measuring units, which are provided on the substrate table PT, arenot limited to those described above. Various measuring units can beprovided, if necessary. For example, a wave front aberration-measuringunit may be arranged on the substrate table PT. The wave frontaberration-measuring unit is disclosed, for example, in InternationalPublication No. 99/60361 (corresponding to European Patent PublicationNo. 1,079,223) and U.S. Pat. No. 6,650,399, the content of which areincorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application. Of course, it is also allowable that nomeasuring unit is provided on the substrate table PT.

The flat surface 30A of the plate member 30, which is formed to have theannular shape, has the width which is formed to be larger than at leastthe projection area AR1 (see FIG. 4). Therefore, when the edge area E ofthe substrate P is subjected to the exposure, the exposure light beam ELis not radiated onto the second plate member 32. Accordingly, it ispossible to suppress the deterioration of the liquid repellence of thesecond plate member 32 which would be caused by the radiation of theexposure light beam. The frequency of the exchange of the second platemember 32 can be made smaller than the frequency of the exchange of theplate member 30. Further, it is preferable that the width of the flatsurface 30A is formed to be larger than the liquid immersion area AR2which is formed on the image plane side of the projection optical systemPL. Accordingly, when the edge area E of the substrate P is subjected tothe liquid immersion exposure, then the liquid immersion area AR2 isarranged on the flat surface 30A of the plate member 30, and the liquidimmersion area AR2 is not arranged on the second plate member 32.Therefore, it is possible to avoid the inconvenience which would beotherwise caused such that the liquid 1 of the liquid immersion area AR2inflows into the gap G as the interstice between the plate member 30 andthe second plate member 32. The width of the flat surface 30A of theplate member 30 is not limited to those described above. It goes withoutsaying that the width may be smaller than the liquid immersion area AR2.

As shown in FIG. 3 and FIG. 5 which is a magnified sectional viewillustrating main parts of the substrate table PT which holds thesubstrate P, the substrate holder PH, which constructs a part of thesubstrate table PT, includes a substantially annular circumferentialwall portion 33, a plurality of support portions 34 which are providedon a base portion 35 disposed inside the circumferential wall portion 33and which support the substrate P, and a plurality of suction ports 41which are arranged between the support portions 34 and which areprovided in order to attract and hold the substrate P. The supportportions 34 and the suction ports 41 are arranged uniformly at theinside of the circumferential wall portion 33. In FIG. 5, the upper endsurface of the circumferential wall portion 33 is depicted to have arelatively wide width. However, the upper end surface actually has onlya width of about 1 to 2 mm. The base portion 35 is provided with holes71 which are arranged with lifting members 70 constructed of pin membersfor moving the substrate P upwardly and downwardly. In this embodiment,the lifting members 70 are provided at three positions. The liftingmember 70 is moved upwardly and downwardly by an unillustrated drivingunit. The control unit CONT controls the upward/downward movement of thelifting member 70 by the aid of the driving unit.

As shown in FIG. 5, a plurality of suction holes 72, which are providedin order to attract and hold the plate member 30 with respect to thesubstrate table PT, are disposed at positions of the upper surface ofthe substrate table PT opposed to the lower surface of the plate member30. Lifting members 74, which are constructed of pin members for movingthe plate member 30 upwardly and downwardly with respect to thesubstrate table PT, are provided at a plurality of positions (threepositions in this arrangement) of the substrate table PT. The liftingmember 74 is moved upwardly and downwardly by an unillustrated drivingunit. The control unit CONT controls the upward and downward movement ofthe lifting member 74 by the aid of the driving unit (see FIG. 7(d)).Further, although not shown, a plurality of suction holes, which areprovided in order to attract and holds the second plate member 32 withrespect to the substrate table PT, are disposed at positions of theupper surface of the substrate table PT opposed to the lower surface ofthe second plate member 32. Lifting members, which move the second platemember 32 upwardly and downwardly with respect to the substrate tablePT, are provided at a plurality of positions of the substrate table PT.

The exchange frequency of the second plate member 32 is small asdescribed above. Therefore, the second plate member 32 may be fixed by,for example, the screw fastening rather than being attracted and heldwith respect to the substrate table PT, and the exchange operation maybe performed manually. It is also allowable that the second plate member32 is not exchangeable.

However, the exposure light beam EL or any light beam having the samewavelength as that of the exposure light beam is radiated onto thesecond plate member 32, for example, when the reference member 300and/or the uneven illuminance sensor 400 is used, it is feared that theliquid repellence of the surface of the second plate member 32 may bedeteriorated. In this case, there is such a possibility that theexchange frequency equivalent to that of the plate member 30 may berequired.

As shown in FIGS. 4 and 5, a predetermined gap A is formed between theplate member 30 and a side surface PB of the substrate P held by thesubstrate holder PH (substrate table PT).

With reference to FIG. 5, the substrate holder PH, which holds thesubstrate P, is arranged in the recess 31 of the substrate table PT. Thesubstrate table PT is formed so that an upper end surface 34A of thesubstrate holder PH is higher than the placing surface PTa of thesubstrate table PT for the plate member 30 and the second plate member32, when the substrate holder PH is arranged in the recess 31. Thecircumferential wall portion 33 and the support portions 34 are providedon the substantially disk-shaped base portion 35 which constructs a partof the substrate holder PH. Each of the support portions 34 istrapezoidal as viewed in a sectional view. The back surface PC of thesubstrate P is held by the upper end surface 34A of the plurality ofsupport portions 34. The upper surface 33A of the circumferential wallportion 33 is a flat surface. The height of the circumferential wallportion 33 is lower than the height of the support portion 34. A gap Bis formed between the substrate P and the circumferential wall portion33. The gap B is smaller than the gap A which is provided between theplate member 30 and the side surface PB of the substrate P. A gap C isformed between the inner side surface 36 of the recess 31 and the sidesurface 37 of the substrate holder PH opposed to the inner side surface36. In this arrangement, the diameter of the substrate holder PH isformed to be smaller than the diameter of the substrate P. The gap A issmaller than the gap C. In this embodiment, any cutout (for example,orientation flat or notch), which is to be used for the positioning, isnot formed for the substrate P. The substrate P is substantiallycircular. The gap A is 0.1 mm to 1.0 mm, which is about 0.3 mm in thisembodiment over the entire circumference of the substrate. Therefore, itis possible to avoid the inflow of the liquid. When any cutout is formedfor the substrate P, the plate member 30 and the circumferential wallportion 33 may be allowed to shapes adapted to the cutout, for example,such that projections are provided for the plate member 30 and thecircumferential wall portion 33 depending on the cutout. Accordingly,the gap A can be also secured between the substrate P and the platemember 30 at the cutout of the substrate P.

An inner stepped portion 30D is formed at an inner portion of the platemember 30. A support surface 30S, which is opposed to the edge portionof the substrate lower surface PC, is formed by the inner steppedportion 30D. The plate member 30 is capable of supporting the edgeportion of the substrate lower surface PC by the support surface 30S. Inthis arrangement, as shown in FIG. 5, a gap D is formed between the edgeportion of the substrate lower surface PC held by the substrate holderPH and the support surface 30S of the plate member 30 held by theplacing surface PTa of the substrate table PT. Accordingly, it ispossible to avoid the occurrence of the inconvenience which would beotherwise caused such that the plate member 30 (support surface 30S)abuts against the edge portion of the substrate lower surface PC, andthe edge portion of the substrate P is warped upwardly.

An inner stepped portion 32D is formed at an inner portion of the secondplate member 32. An outer stepped portion 30F is formed at an outerportion of the plate member 30 so that the outer stepped portion 30F isadapted to the shape of the inner stepped portion 32D of the secondplate member 32. Accordingly, a state is given, in which a part of theplate member 30 is placed on a part of the second plate member 32. Apredetermined gap G is formed between the outer side surface of theplate member 30 and the inner side surface of the second plate member32. In this embodiment, the gap G is, for example, about 0.3 mm. The gapG is interposed by the second plate member 32 and the plate member 30made of polytetrafluoroethylene having the liquid-repellent surface.Therefore, even when the liquid immersion area is formed at the boundarybetween the plate member 30 and the second plate member 32, it ispossible to avoid the inflow of the liquid into the gap G.

The surface PA as the exposure surface of the substrate P is coated witha photoresist (photosensitive material) 90. In this embodiment, thephotosensitive material 90 is a photosensitive material for the ArFexcimer laser (for example, TARF-P6100 produced by TOKYO OHKA KOGYO CO.,LTD.). The photosensitive material 90 is liquid-repellent(water-repellent), and the contact angle thereof is about 70° to 80°.

In this embodiment, the side surface PB of the substrate P is subjectedto a liquid-repelling treatment (water-repelling treatment).Specifically, the side surface PB of the substrate P is also coated withthe photosensitive material 90 having the liquid repellence.Accordingly, it is possible to avoid the inflow of the liquid from thegap A between the side surface of the substrate P and the plate member30 having the liquid-repellent surface. Further, the back surface PC ofthe substrate P is also subjected to a liquid-repelling treatment bycoating the back surface PC with the photosensitive material 90.

In this embodiment, the placing surface PTa and the inner side surface36 of the substrate table PT have the liquid repellence. Further, a partof the surface of the substrate holder PH is also subjected to theliquid-repelling treatment to have the liquid repellence. In thisembodiment, the side surface 37 and the upper surface 33A of thecircumferential wall portion 33 of the substrate holder PH have theliquid repellence. When the liquid-repelling treatment is performed forthe substrate table PT and the substrate holder PH, for example, aliquid-repellent material including, for example, fluorine-based resinmaterials and acrylic resin materials is coated, or a thin film composedof the liquid-repellent material as described above is stuck. Amaterial, which is insoluble in the liquid 1, is used as theliquid-repellent material in order to provide the liquid repellence. Theentire substrate table PT and/or the entire substrate holder PH may beformed of a material having the liquid repellence (for example,fluorine-based resin).

A first space 38, which is surrounded by the circumferential wallportion 33 of the substrate holder PH, is allowed to have the negativepressure by a sucking unit 40. The sucking unit 40 includes a pluralityof suction ports 41 which are provided on the upper surface of the baseportion 35 of the substrate holder PH, a vacuum section 42 whichincludes a vacuum pump provided externally with respect to the substratetable PT, and a flow passage 43 which is formed in the base portion 35and which connects the plurality of suction ports 41 and the vacuumsection 42 respectively. The suction ports 41 are provided at aplurality of predetermined positions of the upper surface of the baseportion 35 except for the support portions 34 respectively. The suckingunit 40 sucks the gas (air) contained in the first space 38 formed amongthe circumferential wall portion 33, the base portion 35, and thesubstrate P supported by the support portions 34 so that the first space38 is allowed to have the negative pressure. Accordingly, the substrateP is attracted and held by the support portions 34. The gap B, which isformed between the back surface PC of the substrate P and the uppersurface 33A of the circumferential wall portion 33, is minute.Therefore, the negative pressure of the first space is maintained.

The liquid 1, which flows into a second space 39 between the inner sidesurface 36 of the recess 31 and the side surface 37 of the substrateholder PH, is recovered by a recovery section 60. In this embodiment,the recovery section 60 has a tank 61 which is capable of accommodatingthe liquid 1, and a flow passage 62 which is provided in the substratetable PT and which connects the space 39 and the external tank 61. Theliquid-repelling treatment is also performed to the inner wall surfaceof the flow passage 62. The liquid, which flows into the space 39, maybe temporarily held on the substrate stage PST (substrate table PT), andthe liquid may be discharged, for example, to an external tank providedseparately from the substrate stage PST at a predetermined timing.

The substrate table PT is formed with a flow passage 45 which connectsthe second space 39 disposed between the inner side surface 36 of therecess 31 and the side surface 37 of the substrate holder PH and thespace (atmospheric air space) disposed outside the substrate table PT.The gas (air) is capable of flowing via the flow passage 45 between thesecond space 39 and the outside of the substrate table PT. The secondspace 39 is approximately set to have the atmospheric pressure.

As shown in FIG. 6, the substrate holder PH, the plate member 30, andthe second plate member 32 are independent parts, and are provideddetachably with respect to the substrate table PT. The contact surface57, of the substrate table PT, which makes contact with the substrateholder PH is subjected to the liquid-repelling treatment to have theliquid repellence. Further, the back surface 58 of the substrate holderPH, which is the contact surface with respect to the substrate table PT,is also subjected to the liquid-repelling treatment to have the liquidrepellence. The liquid-repelling treatment for the contact surface 57and the back surface 58 can be performed, for example, by coating theliquid-repellent material such as fluorine-based resin materials andacrylic resin materials as described above.

Next, an explanation will be made with reference to schematic viewsshown in FIGS. 7 and 8 about the method for exposing the substrate P byusing the exposure apparatus EX constructed as described above.

As shown in FIG. 7(a), the plate member 30 is attracted and held by theplacing surface PTa of the substrate table PT, and the second platemember 32 is also attracted and held by the placing surface PTa of thesubstrate table PT. The substrate P as the exposure process objective isloaded to the substrate table PT by a transport arm (transport unit) 80.In this situation, the lifting members 70 are moved upwardly. Thetransport arm 80 delivers the substrate P to the lifting members 70which are moved upwardly. The lifting members 74 are not moved upwardly.The lifting members 70 are moved downwardly while holding the substrateP delivered from the transport arm 80. Accordingly, as shown in FIG.7(b), the substrate P is arranged inside the plate member 30, and thesubstrate P is held by the substrate table PT (substrate holder PH). Asshown in FIG. 7(c), the control unit CONT performs the supply and therecovery of the liquid 1 by the liquid supply mechanism 10 and theliquid recovery mechanism 20 to form the liquid immersion area AR2 ofthe liquid 1 between the projection optical system PL and the substrateP held by the substrate table PT. The control unit CONT radiates theexposure light beam EL onto the substrate P via the projection opticalsystem PL and the liquid 1 to perform the liquid immersion exposurewhile moving the substrate stage PST which supports the substrate P.

When the edge area E of the substrate P is subjected to the exposure,the exposure light beam EL is radiated onto the flat surface 30A of theplate member 30. As a result of the irradiation with the exposure lightbeam EL, there is such a possibility that the liquid repellence of theflat surface 30A may be deteriorated. If the liquid repellence of theflat surface 30A is deteriorated, for example, the followinginconvenience arises. That is, the liquid 1 of the liquid immersion areaAR2 arranged on the flat surface 30A tends to remain to cause thevariation of the environment in which the substrate P is placed.Accordingly, the control unit CONT exchanges the plate member 30 inwhich the liquid repellence is deteriorated, with a new plate member 30(having sufficient liquid repellence), depending on the deterioration ofthe liquid repellence of the plate member 30 (flat surface 30A).

Specifically, the liquid 1, which remains on the substrate P and/or theflat surface 30A, is recovered by using, for example, the liquidrecovery mechanism 20 after the completion of the liquid immersionexposure process. After that, as shown in FIG. 7(d), the control unitCONT moves the lifting members 74 upwardly after releasing the platemember 30 from the state of being attracted and held. In this situation,the substrate P is also released from the state of being attracted andheld by the substrate holder PH. The lifting members 74 are movedupwardly in a state in which the lower surface of the plate member 30 issupported. In this situation, the lifting members 70 are not movedupwardly. Accordingly, the plate member 30 is separated or away from thesubstrate table PT. In this situation, the support surface 30S of theplate member 30 supports the edge portion of the substrate lower surfacePC. Therefore, the substrate P is moved upwardly together with the platemember 30, and the substrate P is separated from the substrate table PT.As described above, the lifting members 74, which construct theattachment/detachment mechanism for attaching/detaching the plate member30 with respect to the substrate table PT, are capable of detaching theplate member 30 from the substrate table PT together with the substrateP. The transport arm 80 enters the space between the substrate table PTand the plate member 30 having been moved upwardly by the liftingmembers 74. The transport arm 80 supports the lower surface of the platemember 30. The transport arm 80 unloads the plate member 30 which holdsthe substrate P, out of the substrate table PT (substrate stage PST).

The unloaded plate member 30 is exchanged with a new plate member 30. Asshown in FIG. 8(a), the control unit CONT loads a new plate member 30which holds a substrate P as the exposure process objective, to thesubstrate table PT (substrate stage PST) by using the transport arm 80.In this situation, the lifting members 74 are moved upwardly, and thetransport arm 80 delivers the plate member 30 which holds the substrateP, to the lifting members 74 which are moved upwardly. The liftingmembers 70 are not moved upwardly. The lifting members 74 are moveddownwardly while holding the plate member 30 which has been deliveredfrom the transport arm 80. Accordingly, as shown in FIG. 8(b), the platemember 30, which holds the substrate P, is arranged inside the secondplate member 32, and the plate member 30 is held by the substrate tablePT (substrate holder PH). As shown in FIG. 8(c), the control unit CONTperforms the supply and the recovery of the liquid 1 by the liquidsupply mechanism 10 and the liquid recovery mechanism 20 to form theliquid immersion area AR2 of the liquid 1 between the projection opticalsystem PL and the substrate P held by the substrate table PT. Thecontrol unit CONT radiates the exposure light beam EL onto the substrateP via the projection optical system PL and the liquid 1 to perform theliquid immersion exposure while moving the substrate stage PST whichholds the substrate P.

When the liquid repellence of the plate member 30 is not deterioratedyet, the liquid 1, which remains, for example, on the substrate P and/oron the upper surface 30A of the plate member 30, is recovered by using,for example, the liquid recovery mechanism 20 after the completion ofthe liquid immersion exposure. After that, the control unit CONTreleases the substrate P from the state of being attracted and held.After that, as shown in FIG. 8(d), the lifting members 70 are movedupwardly. In this situation, the plate member 30 is attracted and heldby the substrate table PT. The lifting members 70 are moved upwardly ina state in which the lower surface of the substrate P is supported. Inthis situation, the lifting members 74 are not moved upwardly.Accordingly, the substrate P is separated from the substrate table PT.The transport arm 80 enters the space between the substrate table PT andthe substrate P having been moved upwardly by the lifting members 70,and the lower surface of the substrate P is supported thereby. Thetransport arm 80 unloads the substrate P from the substrate table PT(substrate stage PST).

As for the transport arm 80, it is also allowable that a transport armfor transporting the plate member 30 and a transport arm fortransporting the substrate P are provided separately. However, as shownin FIG. 9, the following arrangement is available. That is, a supportsurface 80A of a transport arm 80 is formed to be large so that thetransport arm 80 can make contact with both of the substrate P and theplate member 30. Accordingly, it is possible to support both of thesubstrate P and the plate member 30. Therefore, both of the substrate Pand the plate member 30 can be transported with one transport arm 80.

As explained above, the liquid-repellent plate members 30, 32, which areprovided for the substrate table PT, are provided exchangeably.Therefore, when the liquid repellence of the plate member 30, 32 isdeteriorated, the liquid repellence on the substrate table PT can bemaintained by merely exchange the plate member 30, 32 with the new platemember 30, 32.

When the liquid-repellent material is coated, or the plate member 30, 32is formed of the liquid-repellent material in order to provide theliquid repellence of the upper surface of the plate member 30, 32 on thesubstrate table PT, then the liquid repellence thereof is deterioratedin some cases when the exposure light beam is radiated. In particular,for example, when the fluorine-based resin is used as theliquid-repellent material, and the ultraviolet light is used as theexposure light beam, then the liquid repellence of the plate member 30,32 tends to be deteriorated (tends to become lyophilic orliquid-attractive). In such a situation, the liquid tends to remain onthe plate member 30, 32.

In view of the above, in the embodiment of the present invention, whenthe liquid repellence of the plate member 30, 32 is deteriorated, theplate member 30, 32 is exchanged with the new plate member 30, 32.

Therefore, it is possible to suppress the remaining of the liquid 1 onthe substrate table PT. Even when the liquid 1 remains, the liquid 1 canbe smoothly recovered by using, for example, the liquid recoverymechanism 20. Therefore, the deterioration of the exposure accuracy,which would be caused by the remaining liquid 1, can be avoided. It ispossible to produce the device which can exhibit the desiredperformance.

The plate member 30, which has the flat portion 30A around the substrateP, is loaded and unloaded together with the substrate P with respect tothe substrate table PT. Accordingly, the plate member 30 can be easilyexchanged together with the substrate P with respect to the substratetable PT. Further, the plate member 30 has the flat surface 30A aroundthe substrate P. Therefore, when the plate member 30 is loaded to thesubstrate table PT together with the substrate P and the liquidimmersion exposure is performed for the edge area E of the substrate P,even if a part of the liquid immersion area AR2 of the liquid 1protrudes to the outside of the substrate P, then the shape of theliquid immersion area AR2 is maintained by the flat surface 30A. Theliquid immersion exposure can be performed in such a state that theliquid 1 is satisfactorily retained on the image plane side of theprojection optical system PL, without causing, for example, the outflowof the liquid 1.

The inner stepped portion 30D is provided at the inner portion of theplate member 30 to form the support surface 30S so that the edge portionof the substrate lower surface PC can be supported. Therefore, thesubstrate P can be moved together with the plate member 30 by merelyeffecting the movement while holding the plate member 30. The corner orturning portion is formed as viewed in a sectional view between theplate member 30 and the substrate P by the inner stepped portion 30D.Therefore, even if the liquid 1 enters the gap A between the platemember 30 and the substrate P, the corner functions as a seal portion.It is possible to avoid the inconvenience which would be otherwisecaused such that the liquid 1 inflows into the side of the back surfacePC of the substrate P and the substrate stage PST (substrate table PT).Further, the side surface PB of the substrate P is also subjected to theliquid-repelling treatment. Therefore, it is possible to satisfactorilyavoid the inflow of the liquid 1 from the gap A between the side surfacePB of the substrate P and the plate member 30.

The inconvenience, which would be otherwise caused such that the liquid1 inflows into the first space 38 via the gap B, can be avoided byproviding the liquid repellence for the back surface PC of the substrateP and the upper surface 33A of the circumferential wall portion 33opposed to the back surface PC. Therefore, it is possible to avoid theoccurrence of the inconvenience which would be otherwise caused suchthat the liquid 1 flows into the suction ports 41. The exposure processcan be performed in such a state that the substrate P is satisfactorilyattracted and held.

In the embodiment of the present invention, the liquid-repellingtreatment is performed to the back surface 58 of the substrate holder PHwhich is detachable with respect to the substrate table PT, and thecontact surface 57, of the substrate table PT, which makes contact withthe substrate holder PH. Accordingly, even when the liquid 1 flows intothe second space 39, it is possible to suppress the inflow of the liquid1 into the space between the back surface 58 of the substrate holder PHand the contact surface 57 of the z stage 52. Therefore, it is possibleto avoid, for example, the occurrence of any rust on the back surface 58of the substrate holder PH and the contact surface 57 of the substratetable PT. If the liquid 1 inflows into the space between the backsurface 58 of the substrate holder PH and the contact surface 57 of thesubstrate table PT, a situation arises such that the substrate holder PHand the Z stage 52 are adhered to one another and they are hardlyseparated from each other. However, the separation can be effected withease by providing the liquid repellence.

As for the attachment/detachment mechanism for attaching and detachingthe plate member 30 with respect to the substrate table PT, the liftingmembers 74 are provided to serve as the lifting unit, and the suctionholes 72 are provided to serve as the attracting/holding unit forattracting and holding the plate member 30. Therefore, it is possible tosmoothly perform the operation for exchanging the plate member 30. Thenew plate member 30 after the exchange can be satisfactorily held on thesubstrate table PT.

The inner stepped portion 32D is formed at the inner portion of thesecond plate member 32, and the outer stepped portion 30F is formed atthe outer portion of the plate member 30. Accordingly, the corner isalso formed as viewed in a sectional view at the gap between the platemember 30 and the second plate member 32. Therefore, even if the liquid1 inflows from the gap G, the corner functions as a seal portion. It ispossible to avoid the inconvenience which would be otherwise caused suchthat the liquid 1 arrives at the inside of the substrate table PT.

The outer stepped portion 30F of the plate member 30 can be supported bythe inner stepped portion 32D of the second plate member 32. Therefore,it is not necessarily indispensable that the plate member 30 is held bythe substrate table PT, because the plate member 30 is supported by thesecond plate member 32 when the second plate member 32 is attracted andheld by the substrate table PT. Therefore, as schematically shown inFIG. 10, a space (dent) 130 can be formed in an area of the substratetable PT opposed to the plate member 30. It is possible to realize alight weight of the substrate table PT (substrate stage PST).

In this arrangement, the substrate P is transported by the transport arm80 in the state in which the substrate P is held by the plate member 30.Therefore, a relatively wide area of the substrate P is supported by theplate member 30. Therefore, for example, even when the substrate P islarge-sized, the flexure (warpage) of the substrate P can be suppressedby transporting the substrate P in the state of being held by the platemember 30.

When the liquid repellence of the flat surface 32A of the second platemember 32 is deteriorated, and the second plate member 32 is exchanged,then the second plate member 32 may be unloaded together with thesubstrate P and the plate member 30 by using the transport arm 80 afterthe completion of the liquid immersion exposure for the substrate P,because the second plate member 32 supports the plate member 30. In thisarrangement, lifting members for moving the second plate member 32upwardly and downwardly may be provided in the same manner as thelifting members 74. It is also allowable that the plate member 30 andthe second plate member 32 can be separately unloaded and loaded withoutproviding the inner stepped portion 32D of the second plate member 32.In this arrangement, a transport mechanism may be further provided inorder to unload and load the second plate member 32.

The timing of the exchange of the plate member 30, 32 is determineddepending on the deterioration of the liquid repellence of the flatsurface 30A, 32A as described above. The timing of the exchange of theplate member 30, 32 includes, for example, every interval of apredetermined number of pieces of processed substrates and/or everyinterval of a predetermined period of time. The plate members 30, 32 canbe exchanged at predetermined intervals which are previously prescribed.Alternatively, the relationship between the radiation amount (radiationtime, illuminance) of the exposure light beam EL and the level of theliquid repellence of the plate member 30, 32 is previously determined byan experiment or simulation. The timing of the exchange of the platemember 30, 32 may be set on the basis of the determined result. Thedeterioration of the liquid repellence can be evaluated, for example,such that the flat surface 30A, 32A or the like is observed visually orunder a microscope, a liquid droplet is dripped onto the surface to beevaluated to observe the state of the liquid droplet visually or under amicroscope, or the contact angle of the liquid droplet is measured. Whenthe evaluation as described above is previously recorded in the controlunit CONT while providing the relationship in relation to the totalizedradiation amount of the ultraviolet light such as the exposure lightbeam, the control unit CONT can determine the service life of the platemember 30, 32 or the like, i.e., the exchange time (timing) inaccordance with the relationship.

The exposure apparatus EX can determine the totalized radiation amountof the exposure light beam EL radiated onto the plate member 30, 32 byusing an integrator sensor (not shown) which is capable of measuring theintensity of the exposure light beam EL radiated onto the image planeside of the projection optical system PL. The control unit CONT canmeasure the radiation time (number of radiation pulses) and theintensity of the exposure light beam EL radiated onto the plate member30 and/or the plate member 32 on the basis of the position informationof the substrate stage PST measured by using the laser interferometer 56and the intensity information of the exposure light beam EL measured byusing the integrator sensor. Therefore, it is possible to determine thetotalized radiation amount of the exposure light beam EL radiated ontothe plate member 30 and/or the plate member 32 on the basis of theresult of the measurement. The integrator sensor for measuring theintensity of the exposure light beam EL is disclosed, for example, inU.S. Pat. Nos. 5,728,495 and 5,591,958, the content of which areincorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application.

In the embodiment of the present invention, the control unit CONT judgeswhether or not the exchange of the plate member 30, 32 is required, onthe basis of the contact angle of the liquid on the upper surface 30A,32A of the plate member 30, 32. When it is estimated or predicted thatthe contact angle of the liquid is lowered to be not more than apredetermined angle (for example, 1000) on the basis of, for example,the time of use of the plate member 30, 32 and/or the totalizedradiation amount of the ultraviolet light, it is judged that theexchange of the plate member 30, 32 is required. Alternatively, when itis estimated that the contact angle of the liquid 1 on the surface 30A,32A of the plate member 30, 32 is lowered by not less than apredetermined angle (for example, 10°) as compared with the initialstate on the basis of, for example, the time of use of the plate member30, 32 and/or the totalized radiation amount of the ultraviolet light,it is judged that the exchange of the plate member 30, 32 is required.

It is not necessarily indispensable that the deterioration of the liquidrepellence of the plate member 30, 32 or the like is judged by thecontrol unit CONT of the exposure apparatus EX. For example, theexposure apparatus EX may be connected to a host computer of a factoryor the like in which the exposure apparatus EX is installed so thatvarious data can be exchanged, and the judgment may be made by the hostcomputer.

When the liquid recovery mechanism 20 has a high ability to recover theliquid, there is such a possibility that the liquid can be sufficientlyrecovered even when the liquid repellence of the plate member 30, 32 isdeteriorated. Therefore, the exchange timing of the plate member 30, 32or the like can be also determined while considering the relationshipbetween the ability of the liquid recovery mechanism 20 to recover theliquid and the deterioration of the liquid repellence (decrease in thecontact angle) as well.

The speed of the deterioration and the degree of the deterioration ofthe liquid repellence differ depending on not only the radiation time ofthe exposure light beam EL but also other factors including, forexample, the material for providing the liquid repellence, the liquid,the exposure wavelength, and the temperature. Therefore, it isappropriate that the evaluation data is prepared together with thefactors as described above. This fact also holds in the same manner asdescribed above for the exchange timings of other members to which theliquid repellence is imparted as described below.

In the embodiment of the present invention, the plate member 30, 32 isformed of, for example, polytetrafluoroethylene which is theliquid-repellent material. However, it is a matter of course that theplate member 30, 32 may be formed of any other material having theliquid repellence. Alternatively, for example, the plate member 30, 32may be formed of a predetermined metal, and the surface of the platemember 30, 32 made of metal may be coated with the liquid-repellentmaterial (fluoride such as polytetrafluoroethylene) having the liquidrepellence. As for the coating area of the liquid-repellent material,the entire surface of the plate member 30, 32 may be subjected to thecoating, or only a part of the area including, for example, the flatsurface 30A, which requires the liquid repellence, may be subjected tothe coating.

It is a matter of course that the plate member 30 and the second platemember 32 may be formed of separate materials, and the plate member 30and the second plate member 32 may be subjected to the coating by usingliquid-repellent materials which are distinct from each other. It is notnecessarily indispensable that all of the surfaces of the plate member30 and the second plate member 32 have the liquid repellence at auniform level. It is also allowable that a portion having the strongliquid repellence may be partially provided. It is not necessarilyindispensable that all of the surfaces of the plate member 30 and thesecond plate member 32 have the same or equivalent durability againstthe deterioration of the liquid repellence. It is also allowable thatthe durability against the deterioration of a portion which undergoes alarge radiation amount of the exposure light beam may be strengthened ascompared with other portions. For example, it is preferable that thesurface of the plate member 30 has the durability against thedeterioration which is stronger than that of the surface of the secondplate member 32.

The embodiment of the present invention has been explained such that theplate member 30 is unloaded together with the substrate P when the platemember 30 is exchanged. It is a matter of course that only the platemember 30 may be loaded and unloaded with respect to the substrate tablePT.

The plate member 30 can be exchanged by using the lifting members 74 andthe transport arm 80. However, it is not necessarily indispensable toprovide the lifting members 74 and the transport arm 80 which is capableof transporting the plate member 30. The plate member 30 may beexchanged manually by an operator. In the embodiment described above,the plate member 30 and the second plate member 32 are providedintegrally respectively. However, it is also allowable that the platemember 30 and the second plate member 32 may be divided respectively sothat they can be partially exchanged. Accordingly, it is also possibleto frequently exchange only a portion at which the deterioration of theliquid repellence is seriously deteriorated.

Alternatively, the plate member 30 and the plate member 32 may be formedas one plate member which may be held on the substrate table PT.

In the embodiment of the present invention, as appreciated from FIG. 5,the substrate holder PH and the substrate table PT are detachable.However, the substrate holder PH may be provided integrally with thesubstrate table PT.

In the embodiment of the present invention, the entire surfaces of thesurface PA, the side surface PB, and the back surface PC of thesubstrate P are coated with the photosensitive material 90 in order toperform the liquid-repelling treatment. However, another arrangement isalso available, in which the liquid-repelling treatment is performed toonly the area for forming the gap A, i.e., the side surface PB of thesubstrate P and the area for forming the gap B, i.e., the area of theback surface PC of the substrate P opposed to the upper surface 33A ofthe circumferential wall portion 33. Further, when the gap A issufficiently small, and the material, which is coated to effect theliquid-repelling treatment, has the sufficiently large liquid repellence(contact angle), then the possibility of the inflow of the liquid 1 intothe second space 39 via the gap A is further lowered. Therefore, anarrangement is also available, in which the liquid-repelling treatmentis not performed to the back surface PC of the substrate P for formingthe gap B, and the liquid-repelling treatment is performed to only theside surface PB of the substrate P. It is a matter of course that thesubstrate P, in which the liquid-repelling treatment is not performed toall of the surface PA, the side surface PB, and the back surface PC, canbe also used.

In the embodiment of the present invention, the height of thecircumferential wall portion 33 is lower than the height of the supportportion 34, and the gap B is formed between the back surface PC of thesubstrate P and the upper surface 33A of the circumferential wallportion 33. However, the back surface PC of the substrate P and theupper surface 33A of the circumferential wall portion 33 may makecontact with each other.

In the embodiment of the present invention, the photosensitive material90 having the liquid repellence is coated as the liquid-repellingtreatment for the side surface PB and the back surface PC of thesubstrate P. However, the side surface PB and the back surface PC may becoated with a predetermined material having the liquid repellence (waterrepellence) other than the photosensitive material 90. For example, aprotective layer called “top coat layer” (film to protect thephotosensitive material 90 from the liquid) is coated or formed as theupper layer of the photosensitive material 90 coated to the surface PAas the exposure surface of the substrate P in some cases. The materialfor forming the top coat layer (for example, fluorine-based resinmaterial) has the liquid repellence (water repellence) with a contactangle of, for example, about 110°. Therefore, the side surface PB andthe back surface PC of the substrate P may be coated with the materialfor forming the top coat layer. Of course, any material having theliquid repellence other than the photosensitive material 90 and thematerial for forming the top coat layer may be coated.

In the embodiment of the present invention, for example, thefluorine-based resin material or the acrylic resin material is coated asthe liquid-repelling treatment for the substrate table PT and thesubstrate holder PH. However, the substrate table PT and the substrateholder PH may be coated with the photosensitive material or the materialfor forming the top coat layer. On the other hand, the side surface PBand the back surface PC of the substrate P may be coated with thematerial used for the liquid-repelling treatment for the substrate stagePST and the substrate holder PH.

The top coat layer is provided in order to prevent the liquid 1 of theliquid immersion area AR2 from the infiltration into the photosensitivematerial 90 in many cases. For example, even when the adhesion trace(so-called “water mark”) of the liquid 1 is formed on the top coatlayer, a predetermined process treatment such as the development processcan be performed after removing the water mark together with the topcoat layer, by removing the top coat layer after the liquid immersionexposure. In this procedure, when the top coat layer is formed of, forexample, a fluorine-based resin material, the top coat layer can beremoved by using a fluorine-based solvent. Accordingly, it isunnecessary to provide any unit for removing the water mark (forexample, a substrate-washing unit for removing the water mark). Thepredetermined process treatment can be satisfactorily performed afterremoving the water mark by a simple configuration in which the top coatlayer is removed with the solvent.

In the embodiment described above, the plate member 30, 32 is held bythe substrate table PT in the vacuum-attraction manner. However, it isalso possible to use another chuck mechanism such as an electromagneticchuck mechanism.

Second Embodiment

Next, another embodiment of the present invention will be explained. Inthe following description, parts or components, which are the same as orequivalent to those of the embodiment described above, are designated bythe same reference numerals, any explanation of which will be simplifiedor omitted.

FIG. 11 shows a substrate holder PH which is attached/detached withrespect to the substrate table PT (substrate stage PST). FIG. 11(a)shows a side sectional view, and FIG. 11(b) shows a plan view as viewedfrom an upper position, illustrating the substrate table PT after thesubstrate holder PH is detached.

As shown in FIG. 11, the substrate table PT includes, on an uppersurface thereof (holding surface for the substrate holder PH), a recess157 to which the substrate holder PH is capable of being fitted, aplurality of vacuum suction holes 158 which are provided in the recess157 and which attract and hold the substrate holder PH arranged in therecess 157, and flow passages 159 which are provided in the recess 157as described later on. When the substrate holder PH is fitted to therecess 157, the substrate table PT and the substrate holder PH arepositioned. The vacuum suction holes 158 construct a part of the chuckmechanism for holding the substrate holder PH arranged in the recess157. The vacuum suction holes 158 are connected to an unillustratedvacuum unit. The driving of the vacuum unit is controlled by the controlunit CONT. The control unit CONT controls the vacuum unit to effect theattraction and the holding as well as the release from the holding ofthe substrate table PT with respect to the substrate holder PH by theaid of the vacuum suction holes 158. When the substrate table PT isreleased from the holding, then the substrate holder PH and thesubstrate table PT can be separated from each other, and the substrateholder PH can be exchanged.

In this embodiment, the explanation has been made such that thesubstrate table PT holds the substrate holder PH by the vacuumattraction. However, the substrate holder PH may be subjected to theholding and the release from the holding by another chuck mechanismincluding, for example, an electromagnetic chuck mechanism. In thisembodiment, the explanation has been made such that the substrate tablePT and the substrate holder PH are positioned by using the recess 157.However, for example, the following arrangement is also available. Thatis, the positional relationship between the substrate holder PH and thesubstrate table PT is optically detected, and the substrate holder PH ispositioned at a predetermined position with respect to the substratetable PT on the basis of the result of the detection.

The substrate holder PH has a recess 150 in which the substrate P is tobe arranged, and a flat surface 30A which is substantially flush withthe surface of the substrate P arranged in the recess 150. The flatsurface 30A is provided annularly around the substrate P. A side wallportion 151, which is higher than the flat surface 30A, is formed aroundthe flat surface 30A. The side wall portion 151 is formed continuouslyand annularly around the flat surface 30A. The liquid 1 can be retainedinside the side wall portion 151 (on the substrate P and on the flatsurface 30A).

The substrate holder PH is formed of a material having the liquidrepellence including, for example, polytetrafluoroethylene. Thesubstrate holder PH may be formed of, for example, a predeterminedmetal. At least the flat surface 30A of the substrate holder PH made ofmetal may be coated with a liquid-repellent material (for example,polytetrafluoroethylene) having the liquid repellence. Of course, theentire region of the surface of the substrate holder PH made of metalmay be coated with a liquid-repellent material.

The transport arm 80 is capable of transporting the substrate holder PHdetached from the substrate table PT.

For example, the transport arm 80 can be operated as follows. That is,the substrate holder PH, which holds the substrate P after beingsubjected to the exposure process, is unloaded from the substrate tablePT (substrate stage PST). The substrate holder PH is exchanged withanother substrate holder PH. After that, the another substrate holder PHis loaded to (loaded on) the substrate table PT.

When the substrate holder PH is loaded to the substrate table PT, thenthe transport arm 80 can load only the substrate holder PH, or thetransport arm 80 can load the substrate holder PH which holds thesubstrate P before being subjected to the exposure process.

FIG. 12 shows the substrate holder PH. FIG. 12(a) shows a side sectionalview, and FIG. 12(b) shows a plan view as viewed from an upper position.

With reference to FIG. 12, the substrate holder PH includes a side wallportion 151 which is capable of retaining the liquid 1 as describedabove, a plurality of projections 161 which are formed on a bottomsurface portion PHT of the recess 150, and vacuum suction holes 162which are formed on upper end surfaces of the projections 161respectively. The upper end surfaces of the projections 161 are flatsurfaces. The substrate holder PH supports the substrate P on the upperend surfaces of the plurality of recesses 161. Further, the substrateholder PH attracts and holds the substrate P by the aid of the vacuumsuction holes 162. In this embodiment, the projections 161 are providedat a plurality of predetermined positions of the bottom surface portionPHT of the recess 150 of the substrate holder PH respectively so thatthe supported substrate P is not warped. When the substrate P issupported by the projections 161, a spacing portion 164 is formedbetween the substrate P and the bottom surface portion PHT of thesubstrate holder PH. In this embodiment, the shape of the substrateholder PH, which is viewed in a plan view, is substantially circular.However, the shape may be rectangular.

When the substrate table PT and the substrate holder PH are connected toeach other, the vacuum suction holes 162 of the substrate holder PH areconnected to the flow passages 159 (see, for example, FIG. 11(b))provided on the upper surface of the substrate table PT, via flowpassages 162A formed in the substrate holder PH. The flow passages 159are connected to the vacuum unit. When the control unit CONT drives thevacuum unit, the substrate P, which is supported by the projections 161,is attracted and held via the flow passages 159 of the substrate tablePT, the flow passages 162A of the substrate holder PH, and the vacuumsuction holes 162. Valves 162B, which are constructed of, for example,solenoid-operated valves to be driven under the control of the controlunit CONT, are provided for the flow passages 162A respectively. Theoperation for opening/closing the flow passage 162A can be subjected tothe remote control. The control unit CONT opens the flow passages 162Aby controlling the valves 162B when the vacuum unit is driven, and thecontrol unit CONT closes the flow passages 162A when the vacuum unit isstopped.

Therefore, after the attracting operation for the substrate P by the aidof the vacuum suction holes 162, the driving of the vacuum unit isstopped, and the flow passages 162A are closed by the valves 162B.Accordingly, the negative pressure of the flow passages 162A ismaintained.

Therefore, even when the substrate table PT and the substrate holder PHare separated from each other, the substrate holder PH can maintain theattraction and the holding of the substrate P by allowing the flowpassages 162A to have the negative pressure.

Next, an explanation will be made with reference to a schematic viewshown in FIG. 13 about the operation of the exposure apparatus EXconstructed as described above.

As shown in FIG. 13(a), the substrate holder PH, which holds thesubstrate P as the exposure process objective, is loaded to thesubstrate table PT together with the substrate P by the transport arm(transport unit) 80. As shown in FIG. 13(b), the substrate holder PH isarranged so that the substrate holder PH is fitted to the recess 157provided for the substrate table PT. The substrate holder PH is held bythe chuck mechanism having the vacuum suction holes 158 (FIG. 11). Thecontrol unit CONT drives the vacuum unit to vacuum-attract and hold thesubstrate P by the aid of the flow passages 159, the flow passages 162A,and the vacuum suction holes 162 (not shown in FIG. 13). In thissituation, the valves 162B open the flow passages 162A. As shown in FIG.13(c), the control unit CONT supplies and recovers the liquid 1 by theliquid supply mechanism 10 and the liquid recovery mechanism 20 to formthe liquid immersion area AR2 of the liquid 1 between the projectionoptical system PL and the substrate P held on the substrate table PT bythe aid of the substrate holder PH. The control unit CONT radiates theexposure light beam EL onto the substrate P via the projection opticalsystem PL and the liquid 1 to perform the liquid immersion exposurewhile moving the substrate P held on the substrate table PT (substratestage PST) by the aid of the substrate holder PH. In this situation, thevacuum suction holes 162 are closed by the substrate P which isattracted and held. Therefore, even when the liquid 1 is supplied, theliquid 1 does not inflow into the vacuum suction holes 162. The liquid1, which is disposed on the substrate P and on the flat surface 30A,does not outflow to the outside of the substrate holder PH owing to theside wall portion 151 of the substrate holder PH as well.

After the completion of the liquid immersion exposure for the substrateP, the control unit CONT recovers the liquid 1 remaining on thesubstrate P and on the flat surface 30A by using, for example, theliquid recovery mechanism 20 (see FIG. 2). Subsequently, the controlunit CONT releases the holding of the substrate holder PH having beeneffected by the chuck mechanism including the vacuum suction holes 158.Further, the flow passages 162A are closed by using the valves 162B. Asshown in FIG. 13(d), the control unit CONT unloads the substrate holderPH in a state of holding the substrate P for which the exposure processhas been completed, from the substrate table PT together with thesubstrate P by the transport arm 80. When the substrate holder PH isseparated from the substrate table PT, the flow passages 162A, which areconnected to the vacuum suction holes 162 that attract and hold thesubstrate P, are closed by the valves 162B to maintain the negativepressure state as explained with reference to FIG. 12. Therefore, theattraction and the holding for the substrate P, which are effected bythe upper end surfaces of the projections 161, are maintained.

When the substrate P is transported together with the substrate holderPH, even if the liquid 1 remains on the substrate P and on the flatsurface 30A, then the remaining liquid 1 does not outflow via the flowpassages 162A. The remaining liquid 1 is retained inside the side wallportion 151. Therefore, the remaining liquid 1 does not outflow to theoutside of the substrate holder PH, and the remaining liquid 1 is notscattered into the transport passage as well.

The unloaded substrate holder PH is exchanged with a new substrateholder PH. The control unit CONT loads the new substrate holder PH whichholds the substrate P as the exposure process objective, to thesubstrate table PT (substrate stage PST) by using the transport arm 80(see FIG. 13).

As described above, the substrate holder PH is exchanged in thisembodiment as well. Therefore, it is possible to hold the substrate P bythe substrate holder PH having the surface which is liquid-repellent.

Third Embodiment

The foregoing embodiments have been explained such that the member(plate member 30, second plate member 32, substrate holder PH), whichhas the flat surface 30A around the substrate P, is exchanged dependingon the deterioration of the liquid repellence thereof. However, it isdesirable that any member other than the plate member 30, the secondplate member 32, and the substrate holder PH provided on the substratetable PT has its liquid-repellent surface. It is appropriate that such amember is exchangeable depending on the deterioration of the liquidrepellence thereof. In particular, it is desirable that the member,which makes contact with the liquid 1, has the liquid-repellent surface.It is appropriate that such a member is exchangeable depending on thedeterioration of the liquid repellence thereof. Specifically, theconstitutive members of the reference member 300 and the constitutivemembers of the optical sensors 400, 500, which are used while formingthe liquid immersion area on the surface, may also be exchangeable.

FIG. 14 shows a sectional view illustrating the reference member 300provided on the substrate table PT. With reference to FIG. 14, thereference member 300 includes an optical member 301 which is formed ofglass (CLEARCERAM), and the reference marks MFM, PFM which are formed onthe upper surface 301A of the optical member 301.

The reference member 300 is attached onto the substrate table PT. Asdescribed above, the reference member 300 is arranged in the opening 32Kprovided for the second plate member 32, and the upper surface 301A isexposed. The reference member 300 (optical member 301) is detachablewith respect to the substrate table PT, and the reference member 300(optical member 301) is exchangeable. Concave and convex members or maleand female members, which are fitted to one another in order to positionthe reference member 300 with respect to the substrate table PT when thereference member 300 is reinstalled to a predetermined position of thesubstrate table PT, may be provided for the reference member 300 and thesubstrate table PT.

Alternatively, a magnet and a material to be attracted thereby may beembedded in the reference member 300 and the substrate table PT so thatthe reference member 300 can be positioned with respect to the substratetable PT by the magnetic force. Further alternatively, it is alsoallowable that the reference member can be positioned with respect tothe substrate table PT by the vacuum attractive force. Quartz may beused as the optical member 301.

A gap K, which is, for example, about 0.3 mm, is provided between thereference member 300 and the opening 32K. The upper surface 301A of theoptical member 301 (reference member 300) is a substantially flatsurface which is provided to have approximately the same height as thoseof (be flush with) the surface of the substrate P, the surface 30A ofthe plate member 30, and the surface 32A of the second plate member 32.

Portions of the second plate member 32, which are disposed in thevicinity of the reference member 300, are thin-walled. An end of athin-walled portion 32S, of the thin-walled portion, which is disposedon the side of the reference member 300, is bent downwardly to form abent portion 32T. A wall section 310, which protrudes upwardly, isformed on the substrate table PT. The wall section 310 is providedoutside the bent portion 32T in relation to the reference member 300.The wall section 310 is formed continuously to surround the referencemember 300 (bent portion 32T). The outer side surface 32Ta of the bentportion 32T is opposed to the inner side surface 310A of the wallsection 310. The inner side surface 32Tb of the bent portion 32T isopposed to the side surface 301B of the optical member 301 (referencemember 300). The side surface 301B of the optical member 301, the innerside surface 32Tb and the outer side surface 32Ta of the bent portion32T, and the inner side surface 310A and the upper end surface 310B ofthe wall section 310 are flat surfaces respectively. The thin-walledportion 32S including the bent portion 32T of the second plate member 32is slightly separated from the wall section 310, and a predetermined gap(interstice) is formed therebetween.

The areas of the upper surface 301A and the side surface 301B of theoptical member 301 opposed to at least the bent portion 32T, and theinner side surface 310A and the upper end surface 310B of the wallsection 310 are subjected to the liquid-repelling treatment to have theliquid repellence. The liquid-repelling treatment can be performed, forexample, by coating the liquid-repellent material such as thefluorine-based resin material and the acrylic resin material asdescribed above.

The liquid 1, which flows into the space 370 between the referencemember 301 and the bent portion 32T of the second plate member 32 (wallsection 310), is recovered by a recovery section 380. In thisembodiment, the recovery section 380 includes a vacuum system 383, agas/liquid separator 381 which includes a tank capable of accommodatingthe liquid 1, and a flow passage 382 which is provided in the substratetable PT and which connects the space 370 and the gas/liquid separator381. The liquid-repelling treatment is also performed to the inner wallsurface of the flow passage 382.

It is conceived that the reference member 300 described above may beconstructed to perform the operation for detecting the reference mark,for example, in a state in which the liquid immersion area AR2 of theliquid 1 is formed on the upper surface 301A of the reference member300. However, the upper surface 301A is liquid-repellent. Therefore, theliquid 1 of the liquid immersion area AR2 on the upper surface 301A canbe satisfactorily recovered after the completion of the operation fordetecting the reference mark. It is possible to avoid the inconveniencewhich would be otherwise caused such that the liquid 1 remains. Further,the side surface 301B of the optical member 301 is liquid-repellent, andthe inner side surface 32Tb of the bent portion 32T opposed to the sidesurface 301B is also liquid-repellent. Therefore, the liquid 1 hardlyinflows into the gap K. Therefore, it is possible to avoid theinconvenience of the inflow of the liquid 1 into the space 370. Even ifthe liquid 1 inflows into the space 370, the liquid 1 can besatisfactorily recovered by the recovery section 380. Further, even ifthe liquid 1 inflows into the space 370, it is possible to avoid theinconvenience which would be otherwise caused such that the liquid 1,which inflows into the space 370, rides across the wall section 310, andthe liquid 1 inflows into the substrate table PT to cause the rust orthe like, because the inner side surface 310A and the upper end surface310B of the wall section 310 are liquid-repellent, and the second platemember 32 (bent portion 32T) opposed to the wall section 310 is alsoliquid-repellent. As described above, the wall section 310 functions asa liquid diffusion-preventing wall to avoid the diffusion of the liquid1. A corner is formed as viewed in a sectional view by the bent portion32T at the gap between the second plate member 32 and the wall section310. The corner functions as a seal portion. Therefore, it is possibleto reliably avoid the inflow of the liquid 1 into the substrate tablePT.

Since the reference member 300 (optical member 301) is exchangeable,when the liquid repellence thereof is deteriorated, the reference member300 may be exchanged with a new reference member 300 (having thesufficient liquid repellence) in the same manner as the plate member 30.

When the reference member 300 is used, the measuring light beam islocally radiated onto the mark portion. Therefore, a plurality ofidentical reference marks may be formed on the reference member 300beforehand. When the liquid repellence of the surface of the markportion is deteriorated, another reference mark may be used.Alternatively, the marks may be alternately used for every measurementoperation in order to lower the speed of the deterioration of the liquidrepellence. Accordingly, it is possible to decrease the exchangefrequency of the reference member 300. This procedure is especiallyeffective, because the liquid repellence is quickly deteriorated at theportion including the reference mark MFM for which the measuring lightbeam having the same wavelength as the exposure wavelength is used.

FIG. 15 shows a sectional view illustrating the uneven illuminancesensor 400 provided on the substrate table PT. With reference to FIG.15, the uneven illuminance sensor 400 includes an upper plate 401 whichis formed of, for example, quartz glass, and an optical element 402which is provided below the upper plate 401 and which is formed of, forexample, quartz glass. In this embodiment, the upper plate 401 and theoptical element 402 are provided as an integrated body. In the followingdescription, the upper plate 401 and the optical element 402 will beappropriately referred to as “optical member 404” in combination. Theupper plate 401 and the optical element 402 are supported on thesubstrate table PT by the aid of a support section 403. The supportsection 403 has a continuous wall portion which surrounds the opticalmember 404. As described above, the uneven illuminance sensor 400 isarranged in the opening 32L provided for the second plate member 32, andthe upper surface 401A is exposed. The optical member 404, whichincludes the upper plate 401 and the optical element 402, is detachablewith respect to the substrate table PT, and the optical member 404 isexchangeable. Concave and convex members or male and female members,which are fitted to one another in order to position the optical member404 with respect to the substrate table PT when the optical member 404is reinstalled to a predetermined position of the substrate table PT,may be provided for the optical member 404 and the substrate table PT.Alternatively, a magnet and a material to be attracted thereby may beembedded in the optical member 404 and the substrate table PT so thatthe optical member 404 can be positioned with respect to the substratetable PT by the magnetic force. Further alternatively, it is alsoallowable that the optical member can be positioned with respect to thesubstrate table PT by the vacuum attractive force.

A pinhole 470, through which the light beam can pass, is provided on theupper plate 401. A thin film 460, which includes a light-shieldingmaterial such as chromium, is provided at portions on the upper plate401 except for the pinhole 470. In this embodiment, an optical memberformed of quartz glass is also provided in the pinhole 470. Accordingly,the thin film 460 is flush with the pinhole 470, and the upper surface401A is a flat surface.

An optical sensor 450, which receives the light beam allowed to passthrough the pinhole 470, is arranged below the optical member 404. Theoptical sensor 450 is attached onto the substrate table PT. The opticalsensor 450 outputs a light-receiving signal to the control unit CONT. Inthis arrangement, a space 405, which is surrounded by the supportsection 403, the substrate table PT, and the optical member 404, is asubstantially tightly closed space. The liquid 1 does not inflow intothe space 405. An optical system (optical element) may be arrangedbetween the optical member 404 and the optical sensor 450.

A gap L, which is, for example, about 0.3 mm, is provided between theopening 32L and the uneven illuminance sensor 400 including the opticalmember 404 and the support section 403. The upper surface 401A of theuneven illuminance sensor 400 is a substantially flat surface which isprovided to have approximately the same height as those of (be flushwith) the surface of the substrate P, the surface 30A of the platemember 30, and the surface 32A of the second plate member 32.

Portions of the second plate member 32, which are disposed in thevicinity of the uneven illuminance sensor 400, are thin-walled. An endof the thin-walled portion 32S, of the thin-walled portion, which isdisposed on the side of the uneven illuminance sensor 400, is bentdownwardly to form a bent portion 32T. A wall section 310, whichprotrudes upwardly, is formed on the substrate table PT. The wallsection 310 is provided outside the bent portion 32T in relation to theuneven illuminance sensor 400. The wall section 310 is formedcontinuously to surround the uneven illuminance sensor 400 (bent portion32T). The outer side surface 32Ta of the bent portion 32T is opposed tothe inner side surface 310A of the wall section 310. The inner sidesurface 32Tb of the bent portion 32T is opposed to the side surface 401Bof the support section 403 and the optical member 404 of the unevenilluminance sensor 400. The side surface 401B, the inner side surface32Tb and the outer side surface 32Ta of the bent portion 32T, and theinner side surface 310A and the upper end surface 310B of the wallsection 310 are flat surfaces respectively. The thin-walled portion 32Sincluding the bent portion 32T of the second plate member 32 is slightlyseparated from the wall section 310, and a predetermined gap(interstice) is formed therebetween.

The areas of the upper surface 401A and the side surface 401B of theuneven illuminance sensor 400 opposed to at least the bent portion 32T,and the inner side surface 310A and the upper end surface 310B of thewall section 310 are subjected to the liquid-repelling treatment to havethe liquid repellence. The liquid-repelling treatment can be performed,for example, by coating the liquid-repellent material such as thefluorine-based resin material and the acrylic resin material asdescribed above.

The liquid 1 i, which flows into a space 470 between the unevenilluminance sensor 400 and the bent portion 32T of the second platemember 32 (wall section 310), is recovered by a recovery section 480. Inthis embodiment, the recovery section 480 includes a vacuum system 483,a gas/liquid separator 481 which includes a tank capable ofaccommodating the liquid 1, and a flow passage 482 which is provided inthe substrate table PT and which connects the space 470 and thegas/liquid separator 481. The liquid-repelling treatment is alsoperformed to the inner wall surface of the flow passage 482.

As for the uneven illuminance sensor 400 described above, the pinhole470 is successively moved to a plurality of positions in the irradiationarea (projection area) onto which the exposure light beam EL isradiated, for example, in a state in which the liquid immersion area AR2of the liquid 1 is formed on the upper surface 401A of the unevenilluminance sensor 400. The upper surface 401A is liquid-repellent.Therefore, the liquid 1 of the liquid immersion area AR2 on the uppersurface 401A can be satisfactorily recovered after the completion of themeasurement of the uneven illuminance. It is possible to avoid theinconvenience which would be otherwise caused such that the liquid 1remains. Further, the side surface 401B of the uneven illuminance sensor400 (optical member 404, support section 403) is liquid-repellent, andthe inner side surface 32Tb of the bent portion 32T opposed to the sidesurface 401B is also liquid-repellent. Therefore, the liquid 1 hardlyinflows into the gap L. Therefore, it is possible to avoid theinconvenience of the inflow of the liquid 1 into the space 470. Even ifthe liquid 1 inflows into the space 470, the liquid 1 can besatisfactorily recovered by the recovery section 480. Further, even ifthe liquid 1 inflows into the space 470, it is possible to avoid theinconvenience which would be otherwise caused such that the liquid 1,which inflows into the space 470, rides across the wall section 310, andthe liquid 1 inflows into the substrate table PT to cause the rust orthe like, because the inner side surface 310A and the upper end surface310B of the wall section 310 are liquid-repellent, and the second platemember 32 (bent portion 32T) opposed to the wall section 310 is alsoliquid-repellent. A corner is formed as viewed in a sectional view bythe bent portion 32T at the gap between the second plate member 32 andthe wall section 310. The corner functions as a seal portion. Therefore,it is possible to reliably avoid the inflow of the liquid 1 into thesubstrate table PT.

Since the optical member 404 is exchangeable, when the liquid repellencethereof is deteriorated, the optical member 404 may be exchanged with anew optical member 404 (having the sufficient liquid repellence) in thesame manner as the plate member 30.

The spatial image-measuring sensor 500 is constructed substantiallyequivalently to the uneven illuminance sensor 400. Therefore, anydetailed explanation thereof will be omitted. However, the spatialimage-measuring sensor 500 also has an optical member constructed of anoptical element and an upper plate supported by the aid of a supportsection on the substrate table PT. A slit 570 through which the lightbeam can pass, and a thin film which is formed of a light-shieldingmaterial to cover portions other than the slit are provided on an uppersurface 501A of the spatial image-measuring sensor 500. An opticalsensor, which receives the light beam allowed to pass through the slit570, is provided below the optical member. The optical member, which hasthe slit 570, is exchangeable depending on the deterioration of theliquid repellence.

In the embodiment explained with reference to FIGS. 14 and 15, theinflow of the liquid 1 is avoided by providing the liquid repellence forthe surfaces of the members for forming the gaps K, L. However, theinflow of the liquid 1 into the gap can be avoided by similarlyproviding the liquid repellence for the gap existing on the uppersurface of the substrate table PT, without being limited to the gapsdisposed around the measuring member and the sensor. Alternatively, aseal member, which is formed of a resin or the like, may be arranged inthe gap K, L to avoid the inflow of the liquid 1. Further alternatively,the gap K, L may be filled with a liquid (for example, vacuum grease ormagnetic fluid) to provide the liquid seal function so that the inflowof the liquid 1 is avoided. In this arrangement, it is preferable thatthe sealing liquid is hardly dissolved or eluted in the liquid 1. Ofcourse, it goes without saying that the countermeasures to avoid theinflow of the liquid may be used in combination.

It is unnecessary that all of the surfaces (liquid contact surfaces) ofthe measuring members (for example, the optical member 301 of thereference member 300, the upper plate 401 of the optical sensor 400, andthe upper plate 501 of the optical sensor 500), which are provided onthe substrate stage PST (substrate table PT), are liquid-repellent. Itis also allowable that only a part or parts of them may have the liquidrepellence.

In the embodiment described above, the exchange is performed when theliquid repellence of the surface of the member is deteriorated. However,when a certain member is exchanged, other members, which will reach theexchange timing soon, may be simultaneously exchanged.

In order to recover the liquid (water) more reliably, it is desirablethat the contact angle with respect to the liquid (water) is larger thanabout 80°, desirably not less than 100° (contact angle ofpolytetrafluoroethylene described above with respect to the liquid(water) is about 110°), for example, for the surface of the substratetable PT, i.e., the surface of the plate member 30, the surface of thesecond plate member 32, and the surface of the reference member 300.

It is desirable that the photosensitive material (resist for the ArFexposure light beam) to be used, with which the surface of the substrateP is coated, has the contact angle with respect to the liquid (water)that is larger than about 80°. Of course, when the KrF excimer laserlight beam is used as the exposure light beam, it is desirable to use,as a resist for the KrF exposure light beam, a material which has thecontact angle with respect to the liquid that is larger than 80°.

The specified embodiment described above is illustrative of theexemplary substrate stage which is provided with both of the substratetable and the measuring units or instruments including, for example, thereference member 300, the uneven illuminance sensor 400, and the spatialimage-measuring sensor 500. However, the present invention is alsoapplicable to an exposure apparatus in which a stage for performing theexposure while holding the substrate is distinct from a stage for themeasurement.

That is, the present invention also intends an exposure apparatusprovided with an exposure stage which is movable while holding aprocessing objective substrate such as a wafer, and a measuring stagewhich is provided with various reference members and measuring memberssuch as measuring sensors. In this arrangement, at least a part or partsof the reference members and/or the various measuring sensors arrangedon the substrate stage PST in the embodiment described above can bearranged on the measuring stage. The exposure apparatus, which isprovided with the exposure stage and the measuring stage, is described,for example, in Japanese Patent Application Laid-open No. 11-135400, thecontent of which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

The embodiment of the present invention is also applicable to atwin-stage type exposure apparatus which is provided with two substratestages (substrate tables) for holding the substrate P. The structure andthe exposure operation of the twin-stage type exposure apparatus aredisclosed, for example, in Japanese Patent Application Laid-open Nos.10-163099 and 10-214783 (corresponding to U.S. Pat. Nos. 6,341,007,6,400,441, 6,549,269, and 6,590,634), Published Japanese Translation ofPCT International Publication for Patent Application No. 2000-505958(corresponding to U.S. Pat. No. 5,969,441), and U.S. Pat. No. 6,208,407,the content of which are incorporated herein by reference within a rangeof permission of the domestic laws and ordinances of the statedesignated or selected in this international application.

Fourth Embodiment

FIG. 16 shows a schematic arrangement of a twin-stage type exposureapparatus to which the present invention is applied. The twin-stage typeexposure apparatus includes first and second substrate stages PST1, PST2which are movable on a common base 54 independently respectively. Eachof the first and second substrate stages PST1, PST2 is a substrate stagewhich has the structure and the function as explained in relation toFIGS. 1 to 15. The first and second substrate stages PST1, PST2 havefirst and second substrate tables PT1, PT2 respectively. The platemember 30 and the second plate member 32 are provided exchangeably oneach of the first and second substrate tables PT1, PT2. The twin-stagetype exposure apparatus includes an exposure station ST1 and ameasuring/exchange station ST2. The exposure station ST1 is providedwith the projection optical system PL. The substrate alignment system,the focus/leveling-detecting system and the like are provided on themeasuring/exchange station ST2 (not shown in FIG. 16). The liquidimmersion exposure process is performed for a substrate P held on thefirst substrate table PT1 in the exposure station ST1, during which thesubstrate P is loaded/unloaded with respect to the second substratestage PST2 (second substrate table PT2) together with the plate member30 in the measuring/exchange station ST2. In the measuring/exchangestation ST2, the measuring operation (focus-detecting operation,alignment operation) is performed for a substrate P disposed on thesecond substrate stage PST2 concurrently with the liquid immersionexposure in the exposure station ST1. After the completion of themeasuring operation, the second substrate stage PST2 is moved to theexposure station ST2, and the liquid immersion exposure process isperformed for the substrate P disposed on the second substrate stagePST2.

As described above, in the case of the twin-stage type exposureapparatus, it is possible to perform not only the substrate exchange andthe measuring process but also the exchange of the plate member 30 onthe other stage during the period in which the liquid immersion exposureprocess is performed on one stage. Therefore, it is possible to improvethe throughput of the exposure process.

The respective embodiments described above have been explained such thatthe plate member 30 or the like is exchanged depending on the liquidrepellence thereof.

However, it goes without saying that the plate member 30 or the like canbe exchanged for any reason other than the deterioration of the liquidrepellence, for example, when the plate member 30 or the like is damagedor polluted due to any cause. For example, when the plate member 30 orthe like makes contact with the liquid 1 for a long period of time,there is such a possibility that the surface may be deteriorated, anysubstance may be eluted, and the liquid 1 may be polluted therewith.Therefore, the exchange timing may be also determined in considerationof the surface deterioration of the plate member 30 or the like whichaccompanies the elution of the substance.

In the embodiment described above, the optical element 2 is formed offluorite. However, for example, it is possible to use fluorite in whichthe crystalline orientation of the fluorite surface is the (111) plane.Further, magnesium fluoride (MgF₂), which serves as adissolution-preventive film constructed of a single layer film, may beformed by means of the vacuum vapor deposition method at the end portion2 a of the optical element 2 shown in FIG. 1, i.e., the portion whichmakes contact with the liquid 1.

Fifth Embodiment

For example, when the optical part for constructing the unit such as theradiation amount monitor and the uneven illuminance sensor, the indexplate for the spatial image-measuring unit, and the reference mark(reference member) to be used when the reticle alignment is performedare provided on the substrate stage PST as explained in the firstembodiment, it is desirable that the light irradiated surface (liquidcontact surface) of the optical part as described above has the liquidrepellence. If water is not discharged completely from the lightirradiated surface of the radiation amount monitor, the unevenilluminance sensor or the like, it is feared that the measurement of thelight radiation amount and/or the light illuminance cannot be performedcorrectly. If water is not discharged completely from the surface of theindex plate of the spatial image-measuring unit, there is such apossibility that the surface shape of the index plate may be changed dueto the evaporation of the liquid on the index plate, and any error mayarise in the measurement performed by the spatial image-measuring unit.If water is not discharged completely from the surface of the referencemark, there is such a possibility that the shape of the reference markmay be changed due to the evaporation of the liquid on the referencemark, and the reticle alignment cannot be performed correctly.Therefore, it is required that the surface of the optical part arrangedon the substrate stage has the liquid repellence for a long period oftime.

In such circumstances, it is conceived that an amorphous fluororesin iscoated on the surface of the optical part to form a thin film so thatthe liquid-repellent optical thin film having the high opticalperformance is prepared thereby. That is, the amorphous fluororesin issuch a material that the amorphous fluororesin is especially transparentand it has the high ultraviolet transmittance, as compared with otherresins. Further, the amorphous fluororesin exhibits the smallest surfacetension as compared with any other organic matter, owing to the —CF₃bond coordinated on the resin surface. Therefore, the amorphousfluororesin is also a material which has the excellent water-repellingperformance.

However, in the case of the water-repellent optical thin film formed onthe surface of the optical part, when the ultraviolet laser, which hasthe high energy in the liquid immersion state, is radiated, a minuteamount of the light energy absorbed by the thin film is converted intothe temperature. The thin film is consequently swelled in a relativelyshort period of time, and water inflows into the film. In such asituation, the film is consequently exfoliated if adhesiveness isunsatisfactory between the fluororesin thin film and the surface of theoptical part. The optical performance is harmfully affected thereby, andthe water-repelling performance is deteriorated. Therefore, it is fearedthat any water droplet may remain on the substrate stage.

In general, it is known that a thin film, which has the satisfactoryadhesiveness, is obtained by reacting the optical part surface with acoupling agent such as fluoroalkylsilane to form a binder layer andforming a fluororesin thin film thereon. However, the inventorsperformed investigation and found that the adhesiveness cannot beobtained after the laser irradiation, because fluoroalkylsilane absorbsthe ultraviolet laser beam to consequently cause the decomposition.

In this embodiment, an explanation will be made with reference to thedrawings about an optical part which is capable of maintaining theliquid repellence for a long period of time and which is appropriatelyusable for the liquid immersion type projection exposure apparatus. FIG.19 shows optical parts provided on the wafer stage. FIG. 20 shows anarrangement of the optical part provided on the wafer stage.

The optical parts, which include, for example, a light-entrance window(light irradiated surface) 650 of a radiation amount monitor formonitoring the radiation amount of the exposure light beam, and alight-entrance window (light irradiated surface) 652 of an unevenilluminance sensor for detecting the uneven illuminance of the exposurelight beam, are provided on a wafer stage 609 shown in FIG. 19. Further,the optical parts, which include, for example, an index plate (lightirradiated surface) 654 of a spatial image-measuring unit (AIS system)for measuring, for example, the optical characteristic of the projectionoptical system, and a reference mark (FM) (light irradiated surface) 656to be used when the reticle alignment is performed, are provided on thewafer stage 609. In this arrangement, as shown in FIG. 20, thelight-entrance window (light irradiated surface) 650 of the radiationamount monitor (as well as the light-entrance window (light irradiatedsurface) 652 of the uneven illuminance sensor) is formed of quartz glass660. A particulate layer (adhesive particulate layer) 662, which isformed of silicon dioxide (SiO₂), is formed as a film on the surface ofthe quartz glass 660. A water-repellent film 664, which is composed ofan amorphous fluororesin, is formed as a film on the surface of theparticulate layer.

Each of the index plate 654 of the spatial image-measuring unit (AISsystem) and the reference mark (FM) 656 is composed of quartz glass anda chromium (metal) pattern formed on the surface of quartz glass. Aparticulate layer (adhesive particulate layer), which is formed ofsilicon dioxide (SiO₂), is formed as a film on the surface thereof. Awater-repellent film, which is composed of an amorphous fluororesin, isformed as a film on the surface of the particulate layer.

According to the optical part concerning this embodiment, theparticulate layer, which is composed of silicon dioxide (SiO₂) forforming the adhesive particulate layer, has the good affinity for theglass (main component: SiO₂) of the base material. It is possible toobtain an appropriate degree of adhesiveness with respect to the basematerial glass. Further, irregularities, which result from the diametersof particles, are formed on the surface. Additionally, for example,silicon dioxide itself has the high durability against the laserirradiation as well, because silicon dioxide or the like is a materialhaving the extremely high ultraviolet transmittance. In this embodiment,the particulate layer composed of silicon dioxide (SiO₂) is formed asthe film, and then the water-repellent film composed of the amorphousfluororesin is formed on the particulate layer. The amorphousfluororesin enters voids or interstices of particulates of silicondioxide or the like, and the amorphous fluororesin is subjected todrying and solidification while effecting embrace and inclusion. Themechanical strength of the amorphous fluororesin itself is high.Therefore, the water-repellent film, which is allowed to make tightcontact with the base material, has the high strength.

The water-repellent film, which is formed on the light irradiatedsurface, has the high durability against the laser irradiation.Therefore, it is possible to maintain, for a long period of time, thewater repellence of the light irradiated surface of the optical partprovided on the substrate stage of the projection exposure apparatus.

According to the projection exposure apparatus concerning thisembodiment, the optical part, which makes it possible to maintain thewater repellence of the light irradiated surface for a long period oftime, is provided on the substrate stage. Therefore, even when theliquid immersion exposure is repeatedly performed, it is possible toreliably discharge water from the light irradiated surface of theoptical part.

In the embodiment described above, the adhesive particulate layer, whichis constructed of the particulate layer composed of silicon dioxide(SiO₂), is formed as the film on the light irradiated surface of theoptical part, on which the water-repellent film composed of theamorphous fluororesin is formed as the film. However, an adhesiveparticulate layer, which is composed of magnesium fluoride (MgF₂) orcalcium fluoride (CaF₂), may be formed as a film on the light irradiatedsurface in place of the silicon dioxide (SiO₂), on which thewater-repellent film composed of the amorphous fluororesin may be formedas the film. Alternatively, arbitrary two of silicon dioxide (SiO₂),magnesium fluoride (MgF₂), and calcium fluoride (CaF₂) may be mixed orlaminated to constitute an adhesive particulate layer. Furtheralternatively, three of them may be mixed or laminated to constitute anadhesive particulate layer. Also in this case, it is possible to obtainthe water-repellent film which is excellent in the durability againstthe laser irradiation, in the same manner as in the case in which theadhesive particulate layer constructed of the particulate layer composedof silicon dioxide (SiO₂) is formed as the film, on which thewater-repellent film composed of the amorphous fluororesin is formed asthe film.

In the embodiment described above, the adhesive particulate layer, whichis constructed of the particulate layer composed of silicon dioxide(SiO₂), is formed as the film on the light irradiated surface of theoptical part (for example, the light-entrance window 650), on which thewater-repellent film composed of the amorphous fluororesin is formed asthe film. However, as shown in FIG. 21, an adhesive surface (etchingsurface) 668 may be formed by performing the etching by using hydrogenfluoride (or hydrofluoric acid obtained by dissolving hydrogen fluoridein water) on the surface of the light irradiated surface formed ofquartz glass 666. A water-repellent film 670 composed of an amorphousfluororesin may be formed as a film on the surface of the adhesivesurface 668. In this case, the optical part has, on the light irradiatedsurface, the adhesive surface constructed of the etching surfaceobtained by performing the etching with hydrogen fluoride. Therefore,when the water-repellent film composed of the amorphous fluororesin isformed on the adhesive surface, then the amorphous fluororesin entersvoids or interstices of the adhesive surface, and the amorphousfluororesin is subjected to drying and solidification while effectingembrace and inclusion. The mechanical strength of the amorphousfluororesin itself is high. Therefore, the water-repellent film, whichis allowed to make tight contact with the base material, has the highstrength.

In this embodiment, the light irradiated surface has the base materialglass and the metal film (chromium film) for forming the pattern on thepart of the base material glass, on which the water-repellent filmcomposed of the amorphous fluororesin is formed. However, it is alsoappropriate that a base material glass and a metal film formed on theentire surface of the base material glass are provided, on which thewater-repellent film composed of the amorphous fluororesin is formed.Such an optical part is usable as a high reflection plate to beemployed, for example, when the transmittance of the projection lens ismonitored.

In this embodiment, quartz glass is used as the base material glass.However, it is also appropriate that low expansion glass is used.

The method for producing the optical part according to the embodiment ofthe present invention will be specifically explained below withreference to Examples.

Example A

A surface of a light irradiated surface of an optical part (quartzglass) to be subjected to the film formation is washed to be extensivelyclean by washing the surface with an automatic washing apparatus whichradiates the ultrasonic wave or by wiping the surface with a cloth orthe like impregnated with alcohol.

Subsequently, a coat solution, which is obtained by stably dispersingfine particles of MgF₂ having an average particle size of 80 nm in analkaline solution, is dripped in an appropriate amount onto the surfaceof the optical part to perform the spin coat by using a high speedrotation apparatus. When the coat solution is dried until it loses thefluidity, the optical part is detached from the high speed rotationapparatus, followed by being dried for 1 to 2 hours in a drying furnaceat about 150° C. in order to completely dry the coat solution. A coatsolution, which is obtained by dissolving an amorphous fluororesin(“CYTOP” produced by Asahi Glass Co., Ltd.), is dripped in anappropriate amount further onto the optical part having been cooled toroom temperature to perform the spin coat by using the high speedrotation apparatus. When the coat solution is dried until it loses thefluidity, the optical part is detached from the high speed rotationapparatus, followed by being dried for 1 to 2 hours in a drying furnaceat about 100° C. in order to completely dry the coat solution. Accordingto the steps as described above, the optical part is produced, which hasan MgF₂ film and an amorphous fluororesin film on the base materialglass (quartz glass).

Example B

A surface of a light irradiated surface of an optical part (quartzglass) to be subjected to the film formation is washed to be extensivelyclean by washing the surface with an automatic washing apparatus whichradiates the ultrasonic wave or by wiping the surface with a cloth orthe like impregnated with alcohol.

Subsequently, a coat solution, which is obtained by stably dispersingfine particles of SiO₂ having an average particle size of 80 nm in analkaline solution, is dripped in an appropriate amount onto the surfaceof the optical part to perform the spin coat by using a high speedrotation apparatus. When the coat solution is dried until it loses thefluidity, the optical part is detached from the high speed rotationapparatus, followed by being dried for 1 to 2 hours in a drying furnaceat about 150° C. in order to completely dry the coat solution. A coatsolution, which is obtained by dissolving an amorphous fluororesin(“CYTOP” produced by Asahi Glass Co., Ltd.), is dripped in anappropriate amount further onto the optical part having been cooled toroom temperature to perform the spin coat by using the high speedrotation apparatus. When the coat solution is dried until it loses thefluidity, the optical part is detached from the high speed rotationapparatus, followed by being dried for 1 to 2 hours in a drying furnaceat about 100° C. in order to completely dry the coat solution. Accordingto the steps as described above, the optical part is produced, which hasan SiO₂ film and an amorphous fluororesin film on the base materialglass (quartz glass).

A surface of an optical part (quartz glass), which is polished highlyaccurately to have a roughness of about 0.2 nm RMS, is immersed for 5seconds in hydrofluoric acid diluted to 5%, and then hydrofluoric acidis rinsed with pure water, followed by being wiped with a cloth or thelike impregnated with alcohol. A coat solution, which is obtained bydissolving an amorphous fluororesin (“CYTOP” produced by Asahi GlassCo., Ltd.), is dripped in an appropriate amount onto the surface toperform the spin coat by using a high speed rotation apparatus. When thecoat solution is dried until it loses the fluidity, the optical part isdetached from the high speed rotation apparatus, followed by being driedfor 1 to 2 hours in a drying furnace at about 100° C. in order tocompletely dry the coat solution. According to the steps as describedabove, the optical part is produced, which has an amorphous fluororesinfilm on the base material glass (quartz glass).

Comparative Example

A surface of a light irradiated surface of an optical part (quartzglass) to be subjected to the film formation is washed to be extensivelyclean by washing the surface with an automatic washing apparatus whichradiates the ultrasonic wave or by wiping the surface with a cloth orthe like impregnated with alcohol. Subsequently, a coat solution, whichis obtained by dissolving an amorphous fluororesin (“CYTOP” produced byAsahi Glass Co., Ltd.), is dripped in an appropriate amount onto thesurface to perform the spin coat by using a high speed rotationapparatus.

When the coat solution is dried until it loses the fluidity, the opticalpart is detached from the high speed rotation apparatus, followed bybeing dried for 1 to 2 hours in a drying furnace at about 100° C. inorder to completely dry the coat solution. According to the steps asdescribed above, the optical part is produced, which has an amorphousfluororesin film on the base material glass (quartz glass).

Exfoliation Test

An exfoliation test (tape test) using the cellophane adhesive tape wasperformed for the optical parts obtained in Examples A to C andComparative Example as described above. In the tape test, a cellophaneadhesive tape (JIS-468006) produced by NICHIBAN Co., Ltd. having a widthof 18 mm was used. The degree of exfoliation of the film was judged suchthat the tape was rubbed strongly three times with a finger front whenthe tape was stuck, and then the tape was quickly peeled offperpendicularly. Three samples were prepared for each of the opticalparts obtained in respective Examples, and the test was performed foreach of them.

The following evaluation value criteria were used. That is, a case, inwhich the water-repelling coat was exfoliated in an amount of not lessthan ϕ5 mm, was regarded as “occurrence of exfoliation”. The other caseswere regarded as “no exfoliation”. The expression “3/3” indicates thefact that all of the three samples were exfoliated.

Test Results

Example A 0/3 samples no exfoliation Example B 0/3 samples noexfoliation Example C 0/3 samples no exfoliation Comp. Ex. 3/3 samplesoccurrence of exfoliation

As clarified from the test results, the water-repellent film of each ofExamples A to C is strongly adhered to the base material glass, becausethe adhesive layer or the etching surface is provided. Therefore, it isappreciated that the optical part of the present invention is extremelyexcellent in the liquid resistance (water resistance) in the environmentin which the optical part makes contact with the liquid such as in theliquid immersion exposure.

The embodiment has been explained as exemplified by the case in whichthe water-repellent film is adhered to the base material glass by way ofexample. According to the results as described above, it is appreciatedthat the present invention is usable for arbitrary various opticalparts. That is, the present invention is not limited to various sensorsand reference members provided on the substrate stage of the liquidimmersion exposure apparatus. The present invention can be also used forall optical lenses and optical sensors which are used in such anenvironment that the contact is made with the liquid or the vapor.Further, the present invention is also applicable to the projectionoptical system to be used for the exposure apparatus, especially thelens installed to the end portion disposed on the side of the substrate,the lens to be used for the illumination optical system, and the sensor.

The term “contact angle” referred to in the embodiments described aboveincludes not only the static contact angle but also the dynamic contactangle.

In the embodiments of the exposure apparatus described above, pure wateris used as the liquid 1. Pure water is advantageous in that pure wateris available in a large amount with ease, for example, in thesemiconductor production factory, and pure water exerts no harmfulinfluence, for example, on the optical element (lens) and thephotoresist on the substrate P. Further, pure water exerts no harmfulinfluence on the environment, and the content of impurity is extremelylow. Therefore, it is also expected to obtain the function to wash thesurface of the substrate P and the surface of the optical elementprovided at the end surface of the projection optical system PL. Whenthe purity of pure water supplied from the factory or the like is low,it is also appropriate that the exposure apparatus is provided with anultrapure water-producing unit.

The liquid 1 is water in the respective embodiments described above.However, the liquid 1 may be any liquid other than water. For example,when the light source of the exposure light beam EL is the F₂ laser, theF₂ laser beam is not transmitted through water. Therefore, in this case,liquids preferably usable as the liquid 1 may include, for example, afluorine-based fluid such as fluorine-based oil and perfluoropolyether(PFPE) through which the F₂ laser beam is transmissive. In this case,the portion to make contact with the liquid 1 is subjected to theliquid-attracting treatment by forming a thin film, for example, with asubstance having a molecular structure of small polarity includingfluorine. Alternatively, other than the above, it is also possible touse, as the liquid 1, liquids (for example, cedar oil) which have thetransmittance with respect to the exposure light beam EL, which have therefractive index as high as possible, and which are stable against thephotoresist coated on the surface of the substrate P and the projectionoptical system PL. Also in this case, the surface treatment is performeddepending on the polarity of the liquid 1 to be used.

It is approved that the refractive index n of pure water (water) withrespect to the exposure light beam EL having a wavelength of about 193nm is approximately in an extent of 1.44. When the ArF excimer laserbeam (wavelength: 193 nm) is used as the light source of the exposurelight beam EL, then the wavelength is shortened on the substrate P by1/n, i.e., to about 134 nm, and a high resolution is obtained. Further,the depth of focus is magnified about n times, i.e., about 1.44 times ascompared with the value obtained in the air. Therefore, when it isenough to secure an approximately equivalent depth of focus as comparedwith the case of the use in the air, it is possible to further increasethe numerical aperture of the projection optical system PL. Also in thisviewpoint, the resolution is improved.

When the liquid immersion method is used as described above, thenumerical aperture NA of the projection optical system is 0.9 to 1.3 insome cases. When the numerical aperture NA of the projection opticalsystem is increased as described above, the image formation performanceis sometimes deteriorated by the polarization effect with the randompolarized light beam having been hitherto used as the exposure lightbeam. Therefore, it is desirable to use the polarized illumination. Inthis case, the following procedure is preferred. That is, the linearpolarized illumination is effected, which is adjusted to thelongitudinal direction of the line pattern of the line-and-space patternof the mask (reticle) so that a large amount of diffracted light of theS-polarized component (TE-polarized component), i.e., the component inthe polarization direction along the longitudinal direction of the linepattern is allowed to outgo from the pattern of the mask (reticle). Whenthe space between the projection optical system PL and the resist coatedon the surface of the substrate P is filled with the liquid, thediffracted light of the S-polarized component (TE-polarized component),which contributes to the improvement in the contrast, has thetransmittance through the resist surface that is raised to be high ascompared with a case in which the space between the projection opticalsystem PL and the resist coated on the surface of the substrate P isfilled with the air (gas). Therefore, even when the numerical apertureNA of the projection optical system exceeds 1.0, it is possible toobtain the high image formation performance. It is more effective tomake appropriate combination, for example, with the phase shift maskand/or the oblique incidence illumination method (especially the dipoleillumination method) adjusted to the longitudinal direction of the linepattern as disclosed in Japanese Patent Application Laid-open No.6-188169.

Further, for example, when the ArF excimer laser beam is used as theexposure light beam, and the substrate P is exposed with a fineline-and-space pattern (for example, line-and-space of about 25 to 50nm) by using the projection optical system PL having a reductionmagnification of about ¼, then the mask M functions as a polarizingplate on account of the Wave Guide effect depending on the structure ofthe mask M (for example, the pattern fineness and the chromiumthickness), and a large amount of the diffracted light beam of theS-polarized component (TE-polarized component) is radiated from the maskM as compared with the diffracted light beam of the P-polarizedcomponent (TM-component) which lowers the contrast. In such a situation,it is desirable that the linear polarized illumination is used asdescribed above. However, the high resolution performance can beobtained even when the numerical aperture NA of the projection opticalsystem PL is large, for example, 0.9 to 1.3 even when the mask M isilluminated with the random polarized light beam. When the substrate Pis exposed with an extremely fine line-and-space pattern on the mask M,there is also such a possibility that the P-polarized component(TM-polarized component) may be larger than the S-polarized component(TE-polarized component) on account of the Wire Grid effect. However,for example, when the ArF excimer laser beam is used as the exposurelight beam, and the substrate P is exposed with a line-and-space patternlarger than 25 nm by using the projection optical system PL having areduction magnification of about ¼, then a large amount of thediffracted light beam of the S-polarized component (TE-polarizedcomponent) is radiated from the mask M as compared with the P-polarizedcomponent (TM-polarized component). Therefore, the high resolutionperformance can be obtained even when the numerical aperture NA of theprojection optical system PL is large, for example, 0.9 to 1.3.

Further, it is also effective to use a combination of the obliqueincidence illumination method and the polarized illumination method inwhich the linear polarization is effected in a tangential(circumferential) direction of a circle having a center of the opticalaxis as disclosed in Japanese Patent Application Laid-open No. 6-53120as well as the linear polarized illumination (S-polarized illumination)adjusted to the longitudinal direction of the line pattern of the mask(reticle). In particular, when the pattern of the mask (reticle)includes not only the line pattern which extends in a predetermined onedirection but the pattern also includes line patterns which extend in aplurality of directions in a mixed manner, then the high image formationperformance can be obtained even when the numerical aperture NA of theprojection optical system is large, by using, in combination, the zonalillumination method and the polarized illumination method in which thelinear polarization is effected in a tangential direction of a circlehaving a center of the optical axis as disclosed in Japanese PatentApplication Laid-open No. 6-53120 as well.

In the respective embodiments described above, the optical element 2 isattached to the end portion of the projection optical system PL. Thelens can be used to adjust the optical characteristics of the projectionoptical system PL, including, for example, the aberration (for example,spherical aberration and comatic aberration). The optical element, whichis attached to the end portion of the projection optical system PL, maybe an optical plate to be used to adjust the optical characteristic ofthe projection optical system PL. Alternatively, the optical element maybe a plane parallel plate through which the exposure light beam EL istransmissive. When the optical element which makes contact with theliquid 1 is the plane parallel plate which is cheaper than the lens, itis enough that the plane parallel plate is merely exchanged immediatelybefore supplying the liquid 1 even when any substance (for example, anysilicon-based organic matter), which deteriorates the transmittance ofthe projection optical system PL, the illuminance of the exposure lightbeam EL on the substrate P, and the uniformity of the illuminancedistribution, is adhered to the plane parallel plate, for example,during the transport, the assembling, and/or the adjustment of theexposure apparatus EX. An advantage is obtained such that the exchangecost is lowered as compared with the case in which the optical elementwhich makes contact with the liquid 1 is the lens. That is, the surfaceof the optical element to make contact with the liquid 1 is dirtied, forexample, due to the adhesion of scattered particles generated from theresist by being irradiated with the exposure light beam EL or anyimpurity contained in the liquid 1. Therefore, it is necessary toperiodically exchange the optical element.

However, when the optical element is the cheap plane parallel plate,then the cost of the exchange part is low as compared with the lens, andit is possible to shorten the time required for the exchange. Thus, itis possible to suppress the increase in the maintenance cost (runningcost) and the decrease in the throughput.

When the pressure, which is generated by the flow of the liquid 1, islarge between the substrate P and the optical element disposed at theend portion of the projection optical system PL, it is also allowablethat the optical element is tightly fixed so that the optical element isnot moved by the pressure, rather than allowing the optical element tobe exchangeable.

Each of the embodiments described above is constructed such that thespace between the projection optical system PL and the surface of thesubstrate P is filled with the liquid 1. However, for example, anotherarrangement may be adopted such that the space is filled with the liquid1 in a state in which a cover glass constructed of a plane parallelplate is attached to the surface of the substrate P.

The exposure apparatus, to which the liquid immersion method is appliedas described above, is constructed such that the optical path space,which is disposed on the light-outgoing side of the terminal end opticalelement 2 of the projection optical system PL, is filled with the liquid(pure water) to expose the substrate P. However, as disclosed inInternational Publication No. 2004/019128, it is also allowable that theoptical path space, which is disposed on the light-entrance side of theterminal end optical element 2 of the projection optical system PL, isfilled with the liquid (pure water).

The substrate P, which is usable in the respective embodiments describedabove, is not limited to the semiconductor wafer for producing thesemiconductor device. Those applicable include, for example, the glasssubstrate for the display device, the ceramic wafer for the thin filmmagnetic head, and the master plate (synthetic quartz, silicon wafer)for the mask or the reticle to be used for the exposure apparatus.

As for the exposure apparatus EX, the present invention is alsoapplicable to the scanning type exposure apparatus (scanning stepper)based on the step-and-scan system for performing the scanning exposurefor the pattern of the mask M by synchronously moving the mask M and thesubstrate P as well as the projection exposure apparatus (stepper) basedon the step-and-repeat system for performing the full field exposure forthe pattern of the mask M in a state in which the mask M and thesubstrate P are allowed to stand still, while successively step-movingthe substrate P. The present invention is also applicable to theexposure apparatus based on the step-and-stitch system in which at leasttwo patterns are partially overlaid and transferred on the substrate P.

The embodiments described above adopt the exposure apparatus in whichthe space between the projection optical system PL and the substrate Pis locally filled with the liquid. However, the present invention isalso applicable to a liquid immersion exposure apparatus in which theentire surface of the substrate as the exposure objective is coveredwith the liquid. The structure and the exposure operation of the liquidimmersion exposure apparatus in which the entire surface of thesubstrate as the exposure objective is covered with the liquid aredescribed in detail, for example, in Japanese Patent ApplicationLaid-open Nos. 6-124873 and 10-303114 and U.S. Pat. No. 5,825,043, thecontent of which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

As for the type of the exposure apparatus EX, the present invention isnot limited to the exposure apparatus for the semiconductor deviceproduction apparatus for exposing the substrate P with the semiconductordevice pattern. The present invention is also widely applicable, forexample, to the exposure apparatus for producing the liquid crystaldisplay device or for producing the display as well as the exposureapparatus for producing, for example, the thin film magnetic head, theimage pickup device (CCD), the reticle, or the mask.

When the linear motor is used for the substrate stage PST (wafer stage609) and/or the mask stage MST, it is allowable to use any one of thoseof the air floating type based on the use of the air bearing and thoseof the magnetic floating type based on the use of the Lorentz's force orthe reactance force. Each of the stages PST (609), MST may be either ofthe type in which the movement is effected along the guide or of theguideless type in which no guide is provided. An example of the use ofthe linear motor for the stage is disclosed in U.S. Pat. Nos. 5,623,853and 5,528,118, the content of which are incorporated herein by referencewithin a range of permission of the domestic laws and ordinances of thestate designated or selected in this international application.

As for the driving mechanism for each of the stages PST (690), MST, itis also allowable to use a plane motor in which a magnet unit providedwith two-dimensionally arranged magnets and an armature unit providedwith two-dimensionally arranged coils are opposed to one another, andeach of the stages PST (690), MST is driven by the electromagneticforce. In this arrangement, any one of the magnet unit and the armatureunit is connected to the stage PST (690), MST, and the other of themagnet unit and the armature unit is provided on the side of the movablesurface of the stage PST (690), MST.

The reaction force, which is generated in accordance with the movementof the substrate stage PST (690), may be mechanically released to thefloor (ground) by using a frame member so that the reaction force is nottransmitted to the projection optical system PL. The method for handlingthe reaction force is disclosed in detail, for example, in U.S. Pat. No.5,528,118 (Japanese Patent Application Laid-open No. 8-166475), thecontent of which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

The reaction force, which is generated in accordance with the movementof the mask stage MST, may be mechanically released to the floor(ground) by using a frame member so that the reaction force is nottransmitted to the projection optical system PL. The method for handlingthe reaction force is disclosed in detail, for example, in U.S. Pat. No.5,874,820 (Japanese Patent Application Laid-open No. 8-330224), thecontent of which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

As described above, the exposure apparatus EX according to theembodiment of the present invention is produced by assembling thevarious subsystems including the respective constitutive elements asdefined in claims so that the predetermined mechanical accuracy, theelectric accuracy, and the optical accuracy are maintained. In order tosecure the various accuracies, those performed before and after theassembling include the adjustment for achieving the optical accuracy forthe various optical systems, the adjustment for achieving the mechanicalaccuracy for the various mechanical systems, and the adjustment forachieving the electric accuracy for the various electric systems. Thesteps of assembling the various subsystems into the exposure apparatusinclude, for example, the mechanical connection, the wiring connectionof the electric circuits, and the piping connection of the air pressurecircuits in correlation with the various subsystems. It goes withoutsaying that the steps of assembling the respective individual subsystemsare performed before performing the steps of assembling the varioussubsystems into the exposure apparatus. When the steps of assembling thevarious subsystems into the exposure apparatus are completed, theoverall adjustment is performed to secure the various accuracies as theentire exposure apparatus. It is desirable that the exposure apparatusis produced in a clean room in which, for example, the temperature andthe cleanness are managed.

As shown in FIG. 17, the microdevice such as the semiconductor device isproduced by performing, for example, a step 201 of designing thefunction and the performance of the microdevice, a step 202 ofmanufacturing a mask (reticle) based on the designing step, a step 203of producing a substrate as a base material for the device, an exposureprocess step 204 of exposing the substrate with a pattern of the mask byusing the exposure apparatus EX of the embodiment described above, astep 205 of assembling the device (including a dicing step, a bondingstep, and a packaging step), and an inspection step 206.

INDUSTRIAL APPLICABILITY

According to the exposure apparatus of the present invention, it ispossible to perform the exposure process while suppressing the outflowof the liquid, and it is possible to avoid the remaining of the liquid.Therefore, the liquid immersion exposure can be performed at the highexposure accuracy.

According to the optical part of the present invention, the particulatelayer, which is composed at least one of silicon dioxide (SiO₂),magnesium fluoride (MgF₂), and calcium fluoride (CaF₂) for forming theadhesive particulate layer, has the satisfactory affinity for the glass(main component: SiO₂) of the base material. An appropriate degree ofadhesiveness is obtained with respect to the base material glass. Theirregularities, which result from the diameters of the particles, areformed on the surface. Further, for example, silicon dioxide itself hasthe high durability against the laser irradiation, because silicondioxide or the like is the material which has the extremely highultraviolet transmittance. Therefore, the particulate layer, which iscomposed of at least one of silicon dioxide (SiO₂), magnesium fluoride(MgF₂), and calcium fluoride (CaF₂), is formed as the film, and then thewater-repellent film, which is composed of the amorphous fluororesin, isformed. The amorphous fluororesin enters voids or interstices ofparticulates of silicon dioxide or the like, and the amorphousfluororesin is subjected to drying and solidification while effectingembrace and inclusion. The mechanical strength of the amorphousfluororesin itself is high. Therefore, the water-repellent film, whichis allowed to make tight contact with the base material, has the highstrength. Therefore, the optical part is applicable to optical sensorsand optical instruments to be used in a variety of environments in whichthe optical part makes contact with the liquid.

According to the optical part of the present invention, the adhesivesurface, which is constructed of the etching surface obtained byperforming the etching, for example, with hydrogen fluoride, is providedat the light irradiated surface. Therefore, when the water-repellentfilm, which is composed of the amorphous fluororesin, is formed on theadhesive surface, then the amorphous fluororesin enters voids orinterstices of the adhesive surface, and the amorphous fluororesin issubjected to drying and solidification while effecting embrace andinclusion. The mechanical strength of the amorphous fluororesin itselfis high. Therefore, the water-repellent film, which is allowed to maketight contact with the base material, has the high strength. Therefore,the optical part is applicable to optical sensors and opticalinstruments to be used in a variety of environments in which the opticalpart makes contact with the liquid.

According to the projection exposure apparatus of the present invention,the optical part, which makes it possible to maintain the waterrepellence of the light irradiated surface for a long period of time, isprovided on the substrate stage. Therefore, even when the liquidimmersion exposure is repeatedly performed, it is possible to reliablydischarge water from the light irradiated surface of the optical part.

1. An exposure apparatus which exposes a substrate with light vialiquid, the exposure apparatus comprising: a projection optical systemwhich projects a pattern image onto a projection region on an imageplane of the projection optical system; a stage which holds thesubstrate, the stage being movable relative to the projection opticalsystem; and a liquid supply system which supplies the liquid onto thesubstrate held on the stage to form a liquid immersion area on a part ofthe substrate so that the projection region is located in the liquidimmersion area, wherein the stage comprises: a substrate holder whichholds the substrate, the substrate holder being arranged in a recess ofthe stage to hold the substrate inside the recess so that an uppersurface of the substrate is substantially flush with an upper surface ofthe stage around the recess; a flow passage connected to an internalspace of the recess to remove liquid from the internal space; and asensor which receives light from the projection optical system, thesensor being arranged so that an upper surface of the sensor issubstantially flush with the upper surface of the stage around therecess.
 2. The exposure apparatus according to claim 1, wherein theliquid supply system includes a supply port to supply the liquid ontothe substrate, the supply port being arranged to face the upper surfaceof the substrate inside the recess via the liquid.
 3. The exposureapparatus according to claim 2, further comprising a liquid recoverysystem having a recovery port to recover the liquid from the liquidimmersion region, the recovery port being arranged above the stage so asto face the upper surface of the substrate inside the recess.
 4. Theexposure apparatus according to claim 3, wherein the recovery port isarranged outside the supply port with respect to an optical axis of theprojection optical system.
 5. The exposure apparatus according to claim3, wherein the supply port is arranged outside the projection region,and the recovery port is arranged to surround the projection region andthe supply port.
 6. The exposure apparatus according to claim 1, whereinthe flow passage is connected to a space between an inner side surfaceof the recess and an outer side surface of the substrate holder.
 7. Theexposure apparatus according to claim 1, wherein the substrate holdercomprises a circumferential wall and a supporting portion disposed in aspace surrounded by the circumferential wall, and the substrate holderis configured to hold the substrate on the supporting portion byapplying a negative pressure to the space surrounded by thecircumferential wall.
 8. The exposure apparatus according to claim 7,wherein the substrate holder comprises a plurality of suction ports toapply the negative pressure to the space surrounded by thecircumferential wall.
 9. The exposure apparatus according to claim 8,wherein a height of an upper surface of the circumferential wall islower than a height of an upper surface of the supporting portion. 10.The exposure apparatus according to claim 9, wherein the upper surfaceof the circumferential wall is liquid repellent.
 11. The exposureapparatus according to claim 1, wherein the stage includes a referencemember having a reference mark, of which an upper surface issubstantially flush with the upper surface of the stage around therecess.
 12. The exposure apparatus according to claim 11, wherein atleast a part of the upper surface of the reference member is liquidrepellent.
 13. The exposure apparatus according to claim 1, wherein thesensor includes a light shielding member arranged on at least a part ofthe upper surface of the sensor.
 14. The exposure apparatus according toclaim 13, wherein the light shielding member forms a light transmissivearea in a pinhole shape or a slit shape.
 15. The exposure apparatusaccording to claim 1, wherein at least a part of an upper surface of thesensor is liquid repellent.
 16. The exposure apparatus according toclaim 1, wherein at least a part of the stage is liquid repellent. 17.An exposure method which exposes a substrate with light via liquid, theexposure method comprising: exposing the substrate by use of theexposure apparatus according to claim
 1. 18. The exposure methodaccording to claim 17, wherein the method comprises filling an opticalpath of the light from the projection optical system to the substratebeing supported on the stage with the liquid.
 19. A device manufacturingmethod comprising: transferring a pattern image onto a substrate byexposing the substrate with the exposure apparatus according to claim 1;and assembling a device on the substrate onto which the pattern imagehas been transferred.